I remember when that was doing the rounds a couple years ago, and fans were so annoyed at how low the "expert" valued the collection... probably hoping that they could get dibs on it later when the Pawn people offered an amount that the expert knew would be rejected.
I visited the Toy Shack this year (the store the expert was from) and it even has a sign out the front saying that they are featured on the Pawn Stars show... and it is a huge shop, so this guy would have been experienced enough to know that this collection was worth at least $50,000. The owner said there was over 1000 figures, and he could get $20,000 just from the handfull of city-formers he had in the back corner.
I wish I'd remembered this episode when I was at the Toy Shack, so I could see if this guy was there, and probe his mind for his motives.