You can easily get an 88 weighted keyboard for about 500 bucks.
The yamaha P95 and Casio Privia Px130 are very comparable, and come with two headphone jacks for student/teacher accommodations.
The both have piano, electric, organ, and strings. Neither of them have synth/pads.
Casio Px 130:
88 keys - weighted
About 15 preset sounds if I remember correctly.
Can adjust brilliance a bit.
Can record and play back.
128 note polyphony.
Metronome
Can be used as midi via USB 2 style output.
Can hook up to amp via headphone jacks (might a different impedance though, but it works.)
Yamaha P95:
88 weight keys.
I forget how many preset sounds, but similar to Casio.
64 note polyphony.
Functions with midi via midi output.
Can record and play back.
Two quarter inch jacks that are for phones/output.
Metronome
There is also the CP33 by Yamaha, that goes for about 1,000 before tax. But the first two are both basic without all the bells and whistles for a good price.
www.altomusic.com | Casio PX-130 88-Key Digital Keyboard www.altomusic.com | Yamaha P95 88 Key Digital Stage Piano www.altomusic.com | Yamaha Cp33 Digital Piano