Sounds like a glitch.
Can you list without the New/Used indicated?
Put USED in your title.
Put USED and a description of the wear into your description.
Photograph the worn parts of the item clearly.
After a couple of days, click on Revise and see if the glitch has resolved itself. Then change the Item Specifics.
Hmm-- are you using ithe Simplified Sell Your Item Form, or the Advanced.?