Magento Development - 3 Projects in one

There are actually three projects surrounding the Magento project. They can be done separatly or individually, depending on your experiance, price, and time constraints:
1) The first one is a one-page checkout extension for Magento (this will have to work on multiple websites and can be used on any future Magento websites). I would like to base the programming on http://www.onestepcheckout.com/ product.
2) a extemsion that manages dropshipping for the products (that is, it notifies automatically the dropshippers that the product has been placed). I would like to base this one on http://www.unirgy.com/products/udropship/
3) review the coding of a current Magento project. My programmer thinks it should work but basically we are trying to intergrate all the websites stores into a general mall where we can manage product feeds from a single source. Product additions to the invidual websites should update the mall automatically. We need someone to confirm the code is correct.

What is your price for each of these products individually and a price for all three products? What is the timeframe you can complete these in?

Thanks

Chris