You know what's funny? I was thinking the exactly the same thing as the rest of you: "how the heck am I going to swing getting 13 of those?!?"
I've got enough stickers and forms to send away for four and my fifth certificate is short two stickers.
My current army builder counts are:
German Soldier x4
Russian Soldier x4
Ugha Warrior x4
Cemetary Warrior x2
If I upped my Cemetary Warrior count to 3 which is the number in the movie, upped the other three to six of each and I was already planning on picking up a second Dovchenko to put at the controls of the Jungle Cutter vehicle - those additional eight figures would bring my certificate tally up to six complete certificates.
I know that relics and stickers will be coming with the Last Crusade and Temple of Doom Waves and both of those have six figures each so that would bring my count up to 8. I think I'm going to buy extra Thugee Soldiers from the ToD wave, but even if I picked up only six of those, that would leave my ninth certificate short one sticker.
So even if I grabbed an extra Indy or something, I would still be short four Crystal Skeletons to complete the dio.
I have to say, before seeing the movie, I thought Hasbro had kinda blown it with the mail-away figure. How wrong was I?!?!