I don't think you need worry too much about the motor but the battery is another problem, but not unsolvable. The original rechargeable Deac cells are no longer available and it is quite likely that, if included in the deal, may not accept a charge. On the other hand they/it, (you only NEED one) may still have some life depending on usage and care, or with luck, might have been replaced with the better M/H version. Are you a 'blad user already and does your prospective purchase include a lens? If so, check the slow shutter speeds are not sluggish and the glass is fungus free. Make sure you get the charger as they are difficult to obtain. Replacement M/H batteries are available, in the UK at least, and as erie has said, there are other means. If it's a good deal, go for it - it's a nice piece of kit.
Regards - Allan.