Hi,
I have been developing wesbsites with Joomla since 2008. I'm also familiar with all the features of fiverr.com. If you want a professionally made, SEO optimized, full featured clone to fiverr you will, in my opinion need to significantly increase your budget or you may be disappointed with the final delivery.
That said if the budget you mentioned was just a starting point like in an auction, we can discuss further.
Joomla lacks a CCK (Content construction kit), unlike Drupal for instance. And for this project you need one to be able to define content types for users, service providers and requesters, services offered and so on. So I would recommend the use of a free CCK for Joomla called Seblod.
Seblod will allow you to customize all the features that are required to build a fully functional clone to fiverrr.com. I have a lot of experience with Joomla/Seblod.
It would be helpful if you could share the design you would like for the site. Do you have a psd?
Do not hesitate to contact me if you have any questions. I'm US based which could make communcation easier.
I look forward to hearing from you and start working on your project.
Regards.
Xac.