If the $15/$25 poster reward seems too high, you might be interested in this: we can send you the same poster for just $8 if we fold it for shipping.
After the first few are printed, additional copies of the Concept Art Poster don't cost much to print, and so the main expense is the cost of shipping a mailing tube. This is especially true for international addresses.
However, if I just fold the 11" x 17" sheet in half to 8.5" x 11" , it will ship in a standard-size document envelope, and this is really inexpensive for both USA and International addresses.
So I've added a new reward, which is the same Concept Art Poster that is available (rolled) for $15 or $25, but folded. The layout of the poster is such that the crease will not cross any of the individual portraits (it will go through the logo). See below for a preview (obviously incomplete -- working on Tim and Allen today and there will be some other tweaks).