Purchased as a non runner for £1100 and in a sad state. Every nut and bolt siezed and the bike had been painted with a yard brush.
Plenty of heat and WD40 released the nuts and bolts to dismantle the bike. The rear shocks dumped and new purchased. Seat base solid so had refurbished with new foam, cover and fittings. New chain and sprockets rebuild forks with all new seals. Brake callipers siezed and had to rebuild. Frame parts sent away for powder coating and carbs had to be fully striped down and refurbished. Tank, side panels and rear unit resprayed for under £20 . Most of other items sprayed up as well.
engine wise, very lucky. Dropped the sump to check oil pump filter and clean plus no gunge in sump. So changed filter and fresh oil. The rest was just elbow grease and every nut and bolt refited coated in copper slip. Fitted a new battery and the big bonus for me. The old girl fired up on the button first time. Most owners of the KZ/Z750 have problems with the starter clutch.
Total cost for refurb £ 450.