Software Pricing Issue

Okay, first of all I would like to thank everyone here for helping me with my datacenter questions, you guys are great!

Anyway, I have run into this problem. I have several license keys for sale on ebay. These keys are 100% legit, and they are from microsoft. I was given these product keys as part of a trade with equipment, because the datacenter that had them, no longer needed them and they over ordered. I have:

190 Windows Server 2003 Standard Product Keys
160 Windows Server 2008 Standard Edition x86 Product Keys
190 Windows Server 2008 R2 Standard Edition x64 Product Keys

and my question is, what are they exactly worth. I have a couple of CDs but the product keys are keys with the Certificate. A lady from a datacenter company contacted me and offered $10,000.00 for 190 of the Windows Server 2003 Standard... is it worth it? How much would you sell them for? How would you sell them? Is ebay the right way? I would just like to sell them before they are obsolete.

Thanks a million.

Jim