Well if you just need 1 cable, might as well bite the bullet and pay the high prices. But if you need multiple cables buying a crimper and a big roll of cable saves alot of money. A box of cable holding 250 feet should at the most cost 70-75 bucks, and with a crimper making cables is easy. Last time I needed a cable, I just bought a box of it. Far more cable than I needed, but in the end it will be a better deal.
USB cables, I don't know anything about making those.