Looks like it was introduced in 1998 - I could not find one for sale, so no help on price, but I agree with Gyro in that it is old enough to be behind the curve, and it's price should be modest, no more than a few hundred.....
Here's some info on the board:
•Keyboard: 88 keys (weighted piano-type) •Touch Sensitivity: Preset: 5 levels •Sound Source: Conforms to GM/GS
•Max. Polyphony: 64 voices •Tones: 8 groups, 124 variations (270 in Tone Expansion mode) (incl. 8 drum sets, 1 SFX set)
•Effects: Reverb (8 types), Chorus (8 types), Sympathetic Resonance, Rotary and other 32 types •Music Styles: 8 groups,
111 styles Programmable Music Styles: Yes •Melody Intelligence: 10 types •Metronome: Volume: 10 levels Time
Signature: 0/4, 2/4, 3/4, 4/4, 5/4, 6/4, 7/4, 3/8, 6/8, 9/8, 12/8 •Composer: 5 (ism)/16 tracks Edit: Setup, Copy,
Quantize, Delete, Insert, Erase, Transpose, Track Exchange, Track Copy •Disk Storage: Disk Format: 3.5” FDD
(2DD/2HD) Songs: Max. 99 songs Note Storage: Approx. 120,000 notes (2DD), Approx. 240,000 notes (2HD) •Display:
Graphic 240 x 64 dot backlit LCD Lyrics (for SMF): Yes •Pedals: Damper, Soft/Sostenuto •Rated Power Output: 20W x
2 •Speakers: 16cm x 2 •Finish: Simulated rosewood •Dimensions: 1,387 (W) x 477 (D) x 829 (H) mm •Weight:
And a few sites: http://messe.harmony-central.com/Newp/SNAMM98/Roland/KR-75.html http://achamilton.co.uk/roland_3.htm#KR75
Does not look like a bad machine. I would jump on it if the price was right.....