I agree, the stamp doesn't bother me one bit in a 1 holder like that. If you can pay a 1 price, or a little above, I think it is nice to have a card in better condition that has some extra history and an owner's stamp over a true 1 that is beat to hell and looks either partially or wholly like crap. Now, if this card was a 5 with a stamp (which generally means it would be a 7 without the stamp) I wouldn't be too interested in paying a big price for it when I could get a 5 I would be perfectly happy with that doesn't have the stamp - to me it is relative. There are actually people who collect the stamps (I have a few because I think they are neat, my PB White is attached). You should check out CobbSpikedMe's awesome site (
http://thegreatt206backstampproject.yolasite.com/) for more about stamps.