"Battery needs recharged" that could be a sign the charging system is shot. take a volt meter with you set @20V and place the leads (black/red) to the -/+ sides of the battery while it's running and see what it reads. If it's below 12.5V I would knock him waaaaay down of price. The volts should also increase as the you rev the bike (to a point). I purchased a 77 550K a few years back and the guy was asking $800 for it non running, I picked it up for $400 and with about $200 in tires plus $80 in Misc parts, I rode it for 2 years before I sold it.