My plans are to keep learning to play various music arrangements, and then transition into composing once I'm comfortable playing tunes from the genres of music I'm looking to compose in. The end goal is to compose digitally, there are some features commonly reccomended on this sub that I don't really care about: I probably don't need a full 88 keys, or weighted keys, I don't plan on ever performing live and will be composing digitally with A DAW that can change the sound being used, so I don't think I need a synthesizer that can produce a wide range of sound effects on it's own. I'm less sure on what other sort of features I DO want to make sure the device will have so that I can start learning composition once I get to that stage.

I've been learning on a cheap (<$100) garage sale find, but it's lower keys bit the dust this morning. I've managed to find a Roland GO:Piano88 for $400, and a Yamaha P71B for $300, my budget is $400(+tax/shipping/etc). There is also a Casio CDP-S150 near me for $470 that is marked as usually being $700? Are any of these going to be good for helping me learn and then later compose, or are there other keyboards I should be looking at in the $400 range instead?