Cons: Few sampled sounds
I bought the Casio CPS-7 awhile back for about $500. It has been an excellent portable keyboard for playing at weddings, parties, etc., and for composing/arranging in my den. The sampled sounds are acceptable, if not the greatest.
It has only 76 keys, where a normal piano has 88, but this is not much of a drawback for a portable instrument. Other keyboards often have 66 or fewer keys.
I really like the transposing function for when I accompany a singer that has to sing in a lower or higher key than written!
Here are some specs on this keyboard:
76 full-size keys
5 preset tones: Piano 1 & 2, electric piano, pipe organ, strings
Tone Layering Capability
5 demo songs, one highlighting each tone
Transpose and tuning control
MIDI IN/OUT jacks
Sustain Pedal jack
Operates on 6 D batteries or included AD-12 AC adapter
Fits optional CASIO CS-3 or CS-21 stand
The sustain pedal, which I recommend, is the SP2M and costs about $20.