Bidder #1 (the winning bidder) has only bid once in the last 30 days and he/she bids $16,500? Looks funny to me. High bidder #2 appears to be legitimate. High bidder #3 normally buys reptiles and amphibians and now bids $15,000+ on this lot?
If I had a suspected Picasso, I would have it authenticated so I could get millions for it. On the other hand $644 ain't bad for a pastel drawing done by John Doe Picasso, the caricature artist, down at the art fair.