I would say thats at a push, at the end of the day how much is a engine gony cost? at least £1500 to £2000. then an ecu added together with labour costs, would end up costing about 4k to go on the road, unless the cars got a few good performance parts to go with it i would want to pay no more than a grand, also depends on history and previous mots`s aswell , All I.M.O of course