This question comes up periodically, and asking it here is a bit like asking a barber if you need a haircut. You've got to assume that the answers you are going to get are from people who have self-selected to be here, presumably because they are enjoying roasting and think their results are good.

There are a few ways to look at it. It's not like you have to make a massive decision all at once, so the practical answer is to probably take some baby steps towards getting some good answers. Find some blowhard home roaster near you that's convinced that their coffee is good and buy some roasted coffee from them and see. Or get your hands on some green coffee and a cheap roaster and have a go. Something like a popper or a heat gun/dog bowl is cool because of how hands on it is. Buy, say, 1kg of coffee, roast it all at once; knock out 10 different roasts that are all slightly different; try to cover the full spectrum from too light to too dark, and short to long roast times, full well expecting that the majority of the roasts will be terrible. They will be, but that's not the point; the point is it's a cheap, efficient and fun way of learning how hard roasting is and what flavours you can expect. And part of the reason why making lots of really eggregious mistakes is great is because once you have tasted how green coffee can change with different roasts, it makes it easier for you to recognise less extreme roast defects in other roasts. So that's sort of a non-answer to any of your questions, but it might actually be the most useful thing I have to say.

2) As I mentioned before we use subscription services like Moustache and purchase coffee from professional roasters like counter culture, onyx, wild gift, JBC, etc... As a home roaster enthusiast will I ever be able to roast beans as well as or better than their roasted beans?

Well, the devil in the detail here is, as it always is, what you consider "good" to be. It's also kind of not really a question about whether you can roast as well as they do, it's more a question of how easily and repeatably you can do it, and how long it will take you to learn to do it. All of this sort of comes back to your frame of reference, and I'd say that there are tonnes of commercial roasts that have what I'd consider to be roast defects, but what others would consider to be a stylistic choice.

Personally, I've tried home roasting on and off for something like 15 years and have roasted over 2,000 batches and I don't feel that I can consistently roast as well as the roasters that I really like do. But I'm getting a lot closer. Someone else posted something to the effect of avoiding the spiralling upgrade path in home roasters and starting out with something a little more expensive. I think there's some wisdom in this. I think what you probably would ideally want in a home roaster, as a minimum, is that it would give you control of an independent variable related to the heat/energy (eg. input air temperature or power), it could deliver a repeatable roast state (eg. noting preheating and between batch protocol), you could record the results (eg. artisan/cropster/similar) and it would give you an independent variable to see as an indicator of roast progression (eg. bean temperature). There are also a few other things that are important, but that's kind of the super important things to help you dial in the roast. These are not trivial problems, there are commercially available home roasters that don't have all of these features, and also some that purport to have these features, but really, when you look at them, the implementation is not good, or it's not really these things. To give a really simple example, you want to be able to taste a roast, go "oh, it's too light" and then do something to repeat that same roast, but make it darker, in a predictable and repeatable way. Then you can start to make progress. But, for example, if you made a change to make the roast darker and it didn't work because on your second roast, the roaster wasn't preheated as much, or because you ended the roast based on some temperature indicator and that was unreliable, or because it was colder on that day and your system didn't account for the colder inlet air temperature, or because the thing that you changed didn't play out as you tweaked it to, then you are probably going to chase your tail and get frustrated. There are plenty of machines that you can buy that will be sold to you as finished products that will leave you with these sorts of experiences. Commercial machines, too, from what I'm told!

1) I am concerned about the challenges I would have in sourcing as diverse of an array of green coffee beans as I currently have access to buying from subscription services and professional roasters. Is this a legitimate concern?

Yes, but, as with all things, think through it and see if you nonetheless get somewhere where you are happy.

Again, I think the key to this question is probably what's your frame of reference? Are you generally satisfied with all of the coffees that you get from subscriptions where the roaster or some middleman picks? Or are you the sort that has strong opinions about the coffee variety and the processing technique? Do you have thoughts along the lines of "this XXX variety, YYY process from ZZZ roaster is in a similar genre to the AAA variety, BBB process from CCC roaster that I had DDD years ago, but it's more 111 and less 222 and I like it a lot 333"?

Obviously, coffee roasters have the opportunity to get a wide variety of samples, test and evaluate them and pick what they consider to be the best for their application. As a home roaster, you're not going to do that. Essentially, you are going to substitute the judgment of your coffee roaster and subscription service for the judgment of your green coffee suppliers. You're probably going to buy more coffee from fewer people, so you are going to be more dependent on that judgment.

So, let's step through how this might work in practice. You decide that you want, say, a Brazilian coffee that's kind of chocolatey, nutty, sweet and low acid. How will you get this? You'll probably google and look at what the various suppliers have in stock. So let's say you buy one. Then you roast it. Maybe the results will be good. So maybe you are happy with it, and then it's for you to decide what you do next when you run out. Is it worth trying to find something better? Or do you order again? If you order again, what are you missing out on? How good is it relative to what else is on the market? Or maybe the result is bad. How do you know if it's because of the coffee, or because of the way you roasted it? Was it correctly and reasonably described? I mean, in all likelihood, if you brought it up with the supplier or with home roasters, you'll probably be told that it's of the highest quality and that you didn't roast it well. The description you were probably given was probably not especially specific; it was probably something like "sweet, nutty, low acid, some fruit"; the supplier never said that it wasn't papery and astringent or earthy on the finish; they simply picked a few good aspects and described them to you. So what are you going to do about it? Do you buy more of the same and believe people that your roast was the problem? Do you blindly go buy something different? When you start off, do you maybe buy a selection of different coffees that meet the description of what you're after and go through all of them to work out what you should be buying? These aren't far fetched examples; they are real questions that will inevitably occur to you when you are roasting, so you might as well think about them now.

In some senses, the questions aren't really any different from what a professional roaster faces. The difference is that a professional roaster has access to lots of samples if they want them, and can quickly develop a frame of reference. But some professional roasters just uncritically buy a narrow slice of what's available from one or two suppliers that they trust, so it's not really a given that they will do better, just that it's easier for them to do it. And I've had, defective green coffee like phenolics and mould from both home roast green suppliers and professional coffee roasters, so it's not like the extra layer of QC that you might have if you are buying from a commercial roaster always works. Of course, you can expect that most suppliers will either make advertising puffery style representations about how all of their stuff is high quality, or will be silent as to quality, but you can't really expect that your suppliers are going to give you an honest appraisal of where their green quality sits in the market.

3) Once the learning curve is climbed, how much time does it take to roast a batch? Do coffee roasters have lots of maintenance costs? Clean up time/costs?

This bit sort of varies from roaster to roaster. The popper style roasters can be super small, easy to pull out, set up and go and pack down, and I gather people use some of them with no preheat. They're pretty convenient; no idea about the roast quality. I had a quest M3 that a friend of mine and I highly modified so much that we made the chaff removal useless and had to vacuum the chaff out of it. That was quite a good roaster, actually, and I think we would probably have gotten some really great results out of it if we'd had the patience to keep on modifying it, but part of the reason we gave up on it was because we had so many bread boards and screws and things cobbled together that it was like an hour just to set up, preheat, cool, clean and put away.