I see bikes like that for sale for les than £100 at my local Cash Converters, minus the kit of course. I'd assume the battery is junk - personally, I'd ask what voltage the battery charges to, inspect the cells and look up tests online, measure cell bank voltages, shake my head tutting and make a lowball offer of £150 regardless of the answer and negotiate from there, saying the battery is crap and knackered. The thing might have been left out in the rain for weeks and the display could be invisibly water damaged, cables could be damaged by overtight zipties, bearings might have been crushed or damaged by careless fitting, the battery could have been overegged beyond it's continuous current discharge capability via BBSXXX controller firmware programming... then I'd say shocks are shocking, brakes need upgrading because it's electric, pads discs tyres inner tubes and tyres need replacing, seat is horrible, frame needs stripping painting and new decals, say that BBSXXX motor is illegal, you don't like the look of the warts on his face, his wife is a beast and needs shaving etc. etc. etc. A brand new BBS01B kit without battery costs about £250 from PSWPower, a forum member bought one recently. Explain that such a hairy missus will catch fire easy. Tell the dude this bike is a fireball deathtrap and demand money to take it away from his home.
