hey i have an offer to buy a 1991 gsx 750 for around 6200 USD...the bike is in a lil screwed condition lil bit of rust has crept in...but on purchase it is promised to me with a new paint job..full service tune up and the works required...she still sounds great though, can anyone tell me if this is a good deal to go through with? also im getting a CBR 400 RR and a Kawasaki K-400 both ยด96 models for slightly cheaper...what bike do you think i should go in for??