I've made a large number of upload scripts. I can make you a plain upload script (no design, custom allowed filetypes, backend would be much like drupload.com) for $25. User system, image management (for registered users), and admin system would be $200

You can see my portfolio at http://www.justanotherportfolio.com. I have references on my site and on my iTrader.


As for pre-made scripts you can buy, I have no experience with any of them.