I have a Casio WK-110 piano style digital keyboard in great condition for sale @ $150. This is a discontinued model, but it has received excellent reviews. It has 76 keys, touch response, and MIDI support (through a USB port). You can find videos of people playing this keyboard on Youtube. Personally I am very impressed with how well it sounds.
Please contact me at if you are interested and want to check it out.
Thank you!