OK, speaking as a BUYER on this one...it's the item that's important, NOT the name. I recieved one of the best items I ever won the other day in the mail, but I couldn't tell you the name of the seller

Buyers buy something because they want that particular item, not because they like your user name.
If you like your current name, keep it. And I absolutely agree with the above post - use a seperate account for buying. I always found that to be prudent even before all these changes came about. Whatever you decide, it's your call

... JMHO