Why I don't buy raw stamps from dealers
I broke one of my rules by bidding 0n a used gem(probably a 98) appearing #478 from a big dealer on Ebay. I bought a #11 from them a couple of years ago which was returned from PSE ungraded with a note that it had a crease. I got the #478 today (spent nearly $300) I flip the stamp over and immediately see a perf indent thin in the dead center of the stamp. In fluid it was an obvious dark spot. I would have returned the #11 originally but they only have a 5 day return policy, pretty convenient. Be cautious when you see dealers selling ungraded stamps as gems, they usually aren't.