I've had a few surprises, I got a Juice that was described as "in great working condition" however it was broken. I also got some incredibly dirty tools as well. I think I have a few SAK still sitting in WD40 that I bought months ago.
I did however benefit from the sellers that clearly had no clue what they had. I got a Swisschamp that was being sold as an Explorer. The condition was described great and the price was in my benefit less than 25.
The bay of fleas is a carnival so as the saying goes, caveat emptor.