It depends.... on how they are printed and cut. A 2.5 x 3.5 wallet is in the same ratio or proportion as a 5x7 print. Eight of these (jumbo) wallets will fit in a paper space the size of two 5x7 prints (10x7). But, if you print on 8x10 paper you can actually get 9 slightly smaller wallets with space left over (look in photoshop/file/automate/package).
If you print on 8.5x11 paper you could probably get up to a dozen "wallets" slightly smaller again depending on the ratio/proportion size (2x2.5 for .8 or 8x10 ratio or 2x2.8 prints in the 5x7 ratio.) Something easy to do in photoshop automation.
First question is how do they get cut... by the consumer or by the lab/studio. Lab/studio equipment is usually set up to cut in the larger "jumbo" wallets and cut them slightly smaller due to trimming alignment (might even get rounded corners). If the consumer trims, then no problem... it's them and their scissors.
Second question is the perceived value of different wallet sizes.... less bigger ones or more smaller ones. A tough decision to make.
BTW, the 2.5 x 3.5 jumbo wallets really don't fit very well in most wallet picture holders. My wallet plastic windows hold 2.25x3.25 size pics or other stuff. The 2.5x3.5 wallets need to be trimmed down to fit anyway. Nine of those would fit nicely on 8.5x11 paper with a little room left over.
