126 film is no longer made anywhere. Your only option other than the (not-so)Frugal Photographer is the suspicious stock on ePay.
Althought 126 film is 35mm wide, it is quite different to that used in 35mm cameras, having different perforations, a square picture size, and uses a numbered backing paper in a double-cartridge arrangement.
I've read of some people using 35mm film, or cutting other film to size, to "reload" a cartridge, but it's a very fiddly darkroom procedure. If you just want to try out the camera once, perhaps splash out on a single fresh roll.
Developing to negative should be OK as the width is the same as a standard 35mm, but you might have difficulty in finding a lab who can still print this size of neg optically. (Perhaps you could scan the negs..... )