Interesting concept, just in case it's not clear: It's not like Clever Models where you buy a printed paper structure kit.
What you purchase is a .pdf file to create these kits. It's up to the purchaser to print the kit. You can print it out on your own printer or take it to a copy center to be printed. The good thing is you can then print however many you want.
Personally, right now I have a hard enough time folding paper to fit into an envelope...
Rusty