I understand Type I photos are all the rage, but sometime you may think your getting a 1 of a kind, and it turns out you are not. I've seen the exact same photo by either a Bain, or Thompson or Conlon, but with the stampings in different places on the back or in different condition. So while yes it may be an original don't assume it's a one of a kinf, because it may not be.
Example:
From the HYEE Auction that just ended Sunday:
http://cgi.ebay.com/1910-s-Original-...ts_Memorabilia
Now from a Legandary Auction that ended last year:
http://www.legendaryauctions.com/Lot...x?lotid=102196
Same exact photo on the front, but different markings and condition. So while the purchaser may have thought they got a one of a kind, there is a exact same one out there, and maybe more.
Sorry to be a little skeptical, but I think people are sometimes overpaying, thinking they are getting a one of a kind, and in a sense they are, but then again, they may not be.