I had a problem buying this stuff back when it was considered cheap, in like 97-01. Eventually I realized that I was just not going to be a great pianist and my focus was better spent on drums, where I actually am pretty talented.
The amount and cost of these cheap synths is nuts. It takes considerable willpower to keep from buying them,
especially the cheap
Behringer ARP and
Moog clones.
To scratch my itch, I have the official Moog apps, which are actually really fucking good. If you keep an eye out, Moog will occasionally just give one or two away for free for a weekend (they usually do this at Black Friday, so watch their Instagram), which is how I got mine. I picked up a basic AKAI midi keyboard for $20 on Craigslist, so I can plug that thing into my little Mac Mini or even my iPhone and futz around with their Model 15 modular. Highly recommended if you're a very casual hobbyist who isn't looking to dump a bunch of money into gear.