Save yourself a few bucks and build one! Sure, it's a photo etched parts bender, but I suspect one could adapt it to paper bends and folds as well... I'll let you know when I get around to building one myself!
I have a 36" one for metal, and have though of miniaturizing one for paper. What this guy makes is kind of neat, but without the handle and flat surface to do the bending, tiy rusk deforming the part that is being pushed up. This could easily be modified to add a bar with an arum on it, and two pivot points on the sides to give the a really perfect sheet meta;/paper bender.
The pic below follows the basic construction of what is a better design, and this could be made any size you want.
It's a mess right now. My Barn has too much stuff, my M.G. takes up a lot of spacee, and my motorcycle is in there too. This Spring I plan to rent a container, and do a really big clean out. I have a lot of metal stock. My wife ates it, but a 110' x 2" 3" of T6061 Aluminum, with the serial number and batrch number costs a fortune, combine that with stainless steel, Brass Rods, Steel tubing, aluminum extrusions, I just don't want to recycle this stuff, it would cost me a fortune to replace, and I can make so much out of this stuff. I'm a metal hoarder.
My Barn:
My recumbent Trike, I designed and built (I tend to build functional 1:1 scale models), disc brakes, rear swing arm and 24 speeds:
I can actually cruise easily at about 20 mph on that trike, sorts sprints to 24, but I have a bad back. I have friends who really haul butt on this thing.