That would be a cheap price to pay but in my opinion I feel they would be knackered coming from a school. If you did go for them and it was me I would want to put each of them through their paces before I bought them.
I wish I was close enough to buy them. If the motors are OK, there's not really anything to go wrong. Even if the bearing weren't oiled, they are easy to change, and the bearings in the link arm are dirt cheap. Of course, this is assuming the kids haven't thrown them around the room and bent the arms or something equally disastrous.
