Is this the B25 that sold on VC? If so, I wouldn’t be worried at all of it being a scam since the bag will be sent to VC, and the sale is finalized once they authenticate it. The buyer has already been charged the price. Also, usernames on VC are automatically generated with numbers unless someone changes it, so that also doesn’t indicate anything.
As for whether or not to sell it, I too would be conflicted, and the decision is a personal one that only you know what is the best decision.
The common method they do is they will claim the bag is fake / damaged / lost / never received and VC may very well side with the “buyer”. Then it becomes a case of he said she said. The scammer may also be using a fake name and address with VC. Googling will give you some example stories!