There are WAY to many veiltails already. Biologically, nothing is stopping you from breeding them. (Unless that wasn't a typo and you really ARE trying to breed two males...) If you want more fish, buy more fish. If you want to raise a young betta for the rewarding aspect, I'm sure a little research can help you track down VT babies in your area that needs a home. Please try to be responsible.
Exactly what LoachLover said. Breeding veiltails isn't that difficult it's should you breed them. Imagine this: 100+ bettas, all veil tails, petstore I highly doubt would buy them if you plan to sell. It's you're decision. Veiltails cost only a buck at my lfs.