Bump...
You already have a negative feedback, its going to be hard for you to have a business partner who would assume good faith from you. I don't even think selling Microsoft keys is legal. I believe they are to be along with the CD installer for someone who bought those CD. I'm no microsoft user but I still think you are about to cheat them. Its not how it should work.
Those users who gave you red feedback may have also thought of this. You know for the fact Microsoft keys aren't for sale and yet you do it. That doubles the violation.
I do not care what thy think about me, a lot of people are selling Microsoft keys online, even on eBay. go ahead and stop them if you can.