I'm not quite sure what category this goes to so bare with me. I would like You to help me build a similar system to Ebay and I say that just so you have an easier idea of what I mean. Another (spanish) website is www.mercadolibre.com for reference.
The idea is quite simple.
1. Membership site (that I know to do in wordpress if that's possible to integrate with my the following points)
2. A form where members can fill in Title, Description, Photo, Video and checkboxes for different options and extras.
3. A payment page for that member with a price depending on the options chosen in the form in step 2. Payment with credit card and Paypal (maybe more options?)
4. This information is sent to an administrator (ex. me) for review so it's legit and doesn't contain offensive material that's not in line with the terms. If accepted, the information will turn into a post/page (like a product page on Ebay) with the possible photo and video in right size (i.e. need a re-size function) and maybe in other places, like the different side and top bars with small photos or/and the video to show people "newest uploads".
If declined, the administrator will have a pre-filled mail to explain why and then can add some extra text so the member understand further why he/she was declined.
It should be as automated as possible, all the way through the re-sizing of video and photo to fit the places it should be sent to (sidebars, page)
Hope this make sense and someone out there have the skills and passion to make this.