We made our own by taking a regular button and sewing it back-to-back with a decorative button. The smaller regular button slid through the Croc hole, but the larger decorative one did not. They looked 100% the same as the expensive official variety, were cheaper, were more personalized and were fun to make.
something is wrong. 

! Instead, I've been selling them on eBay for a couple of years so I do know a thing or two about them. If anyone ever has a question about 'em I'd be happy to try and answer it for you! 
