Greetings,
We have read Project Description & understand the initial high level requirements/features mentioned by you but I am not sure why you are going for Joomla CMS? Because this kind of custom Application must be developed from scratch using some strong framework like CodeIgniter, Yii or Zend, because this way you will have a very light weight Application, scalable and easy to enhance in the future. While Joomla self is a bit heavy CMS butI am not saying that Joomla is bad, it is just that if some of the features were already available in Joomla, then we could customize it. However, again decision is yours, as it is my responsibility to give you an idea.
Please drop me a message thru' PMB to start further discussion about your project, as we cannot write much on this initial message bard due to limitation of characters.
Our current bid is just a ballpark estimate but once you respond us, we can then negotiate it & finalize, as we are flexible in prices.
Please check out our Freelancer profile https://www.freelancer.com/u/leadconcept.html, as we have delivered many successfully projects lately and let me know, if you want to see some of our recently developed projects.
Look forward to hearing from you.
Regards,
YK
LEADconcept