Above are the monster card inserts that came inside the fabulous SPP monster wallets:
They can be inserted into plastic sheets and kept in standard card or stamp binders.
If you're just thinking in terms of the Ultra Pro sheets sold in baseball card shops, you are indeed going to be limited to 8.5" x 11" in size:
Here are close-up shots of a couple of Horrorhunter's vending machine cards:Any and all those wild cool treasures for only a nickel! I mean how could a kid say "No"? Unless he was as per usual penniless of course.
found this image on the net - Frankenstein / Dracula Aurora Coppersmith Kit