I am going to start taking piano lessons and would like to get a simple keyboard to practice on. I am looking for suggestions about what brands and features to look for or avoid.
Requirements:
Must sound decent. If what I’m playing sounds like ass, I want it to be my fault.
Must be fairly inexpensive ($100 - $200 or so). Even better if I can get a used one on eBay.
Must have fun features like being able to re-tune it to quarter-tones and stuff like that.
Thanks. 
You want to sound nice, be retunable, and (I surmise) have a piano-like action?
I think you should revise your budget estimate upwards. Way upwards.
Find a used Yamaha PSR-530. Meets all your requirements.
I’ve seen them on E-bay for $150-200.
That’s what I use in my band. Best piano sounds I’ve heard.
Only drawback, no piano-like action. But it does have a sustain pedal input and dynamic action, so the harder you hit the key, the louder the sound will be.
And besides, when you start to explore it, the keyboard is downright fun. And that’s important.
I don’t care much about the piano-like action, as long as I can bang on a key and get noise I’m happy.
Thanks for your suggestion, Rico. I’ll keep an eye out for one of those.
actually, pretty much any of the Yamaha PSR’s will do. Even the cheap ones are built well and can do pretty good piano sounds for a beginner. I would recommend them over their competition Casio.
I’ll chime in on the PSR recommendation as well. We picked one up a while ago, and it has some nice learning features, tons of fun doodads, and mostly, an excellent piano sound.
friedo, if you are serious about taking piano lessons then you need to rethink your drink.
Your lessons will most likely be on a real piano. Its keys have a completely different action when compared to a cheap “synth” type keyboard. Pianos have what is known as a “weighted action.” This mechanism permits the key (and hammer) to fall back into position after being struck / striking the string. A synth keyboard that is velocity sensitive (key hit harder = louder note) is not enough. You will not be training yourself to play real pianos with a cheesey little electronic keyboard. You will actually be defeating your piano lessons by teaching your hands to play on a synth style keyboard. You will not build your muscles and your timing and rythym will be off.
Save your pennies and look for a used Fatar keyboard or any other weighted action type keyboard. Anything less will make you waste your money on the lessons. Whatever you do, make sure that the keyboard you purchase has FULL SIZED KEYS. Buying a 3/4 size keyboard is pure poison. It will give you an artificially longer reach and ruin your hand coordination on a real piano.
Zenster has already said what I was going to say. If you plan on using the keyboard to supplement your piano lessons and practice actual piano technique, then it behooves to you get a digital piano or other weighted action keyboard. Unfortunately, these don’t come cheap.
My own keyboard is a Korg SP-200. It sounds like a real piano; actually, several pianos, organs, harpsichord, and clavichord, plus strings, guiatar and voice for good measure. It was really only the piano I was interested in, the other sounds were a nice bonus. It’s a full-sized keyboard with full-sized keys and, most importantly, feels like a real piano.
a) It should have 88 keys. Do not compromise. If you’re going to play from sheet music you’ll need all the keys the composers expect you to have. Besides, the 72 and 64 and otherwise-shortened keyboards cut into your bass and you’ll miss it.
b) Texture DOES matter. It may not matter to you now but it will. The harder you strike the louder it should get, without a sense of “stair-stepping”. It should feel smooth and linear. 1.03% as hardly struck should equal 1.03% as loud.
c) Polyphony. Again, may not matter to you yet, but it will. The magic cutoff number is 32. 64 is far better if you can get it. Those are the number of notes that will keep on making sounds before the oldest ones disappear in favor of the newest ones, while you are trying to keep them all ringing.
Ours is a Roland. Yamaha makes some nice models we also looked at.