What I always tend to do with oscilloscopes, is look at the ones that are local to me so that I can go and collect it to eliminate the chances of it being damaged in transit. The other advantage is also of course is that often you are able to see it working fully before paying for it. Yes, with eBay, you can agree to pay cash on collection so that would prevent a similar situation from happening again in the future. That way, if you're not happy with the condition of the scope for whatever reason, you can simply walk away from the deal. Also of course, if the seller is local to you, then often they will allow you to pop round and have a little play with the scope before you bid on it, in much the same way as you would if bidding on a car on eBay, you would certainly want to inspect and have a quick test drive of a car, yes?
Keep us updated.