I know $900-$1500 is "cheap" for most of the HN crowd, but for the rest of us there's hardware synth options that are much cheaper! For example, the Korg Volca Keys [1] is a perfectly suitably synth to learn the basics of analog synthesis and can make some nice sounds to boot. YOu can get it for $150 new or even less used. (And of course, there's plenty of free software synths, as others have linked in other posts here). [1] https://www.korg.com/us/products/dj/volca_keys/