I agree with TheChair about MIDI. It's a different thing entirely.
I use an M-Audio "dumb" keyboard that produces no sound at all. (You can't plug it into an amplifier.)
MIDI is just a serial stream of instructions which tell computer software what note you're playing/how loud/duration etc.
Any old (analogue) keyboard will do what you want.
Just look for something in your price range with the ordinary jackplug output that TheChair has described.
Things to consider are number of keys. You may not need the full 88.
Shorter ones tend to be cheaper.
Also, keys can be fully weighted (pukka professional instruments.) You shouldn't need that.
Semi-weighted: nice compromise, and cheaper.
And NOT weighted at all. If you just want to record, then that would be fine. (Proper keyboard players can get sniffy over this and generally go for fully-weighted, especially for stage work.)