I also saw a post where someone bought a new Mogul for $99.00. I was very curious so I called the listed phone numbers for the Ebay vendors and as luck would have it...I could not get anyone on the phone. Reviewing the feedback and everything else the vendors looked legit, but not being able to reach anyone I thought I would give Sprint a call to see what they could do. I expected them to say "yeah right" but instead was very surprised to hear the rep on the other end say "sure we can do that" (that is of course after he talked to a supervisor to get approval). So I now have a 6700 and a Mogul up and running at the same time. (I'm keeping my 6700 working until they get all of the Bluetooth, Sprint TV, Sprint Music, and Telenav issues worked out) Maybe this is why they were willing to make a deal.
Since you are already a Sprint customer and your contract is about to expire...it is worth a try.
Good Luck!