internet site (updated)

I want to have a internet site that, automobile resellers will logon and add their cars in their portfolio, and the people will be free to visit the site (no logon information for the visitors) Something like a shopping site, but in this case the firms will be replaced to car resellers. data will be stored in Microsoft SQL server, photos of the cars will be stored in folders which will be automatically created when a reseller builds up a user for himself. There will be search places for the cars in the site...... On the add before this I had forgotten to write the budget is at most 300$