Greetings,
I understand that you want a website similar to Freelancer or Elance but please note that both websites have loads and loads of features, because they are big, while your budget of US $750 is definitely very low, if you want all the features of Freelancer or Elance but if you have specific list of tasks/features, then we can give you our precise estimate.
Of course, our bid is just to submit the proposal and start communication.
Look forward to hearing from you and talking to you further thru' Freelancer message board.
Regards,
YK
LEADconcept