Blair - a thought,

Mary has now perhaps stepped over a line as far as 
eBay is concerned.  You might ask a helpful bidder 
if he or she would forward the email Mary sent to 
eBay and then yourself follow up with the idea 
that if bidders believe Mary, they will not bid on 
your auctions, reducing the final value fees that 
eBay collects from you.  

Basically, what she is doing now could very well 
impact eBay in the pocket, and they might be more 
receptive to finally ending Mary's reign of 
nonsense.  

If I were in your situation, I would also submit 
proof (if you can) of Mary's harassment of you via 
unwanted junk email to show that it is a personal 
attack by one eBay member on another.  It might 
help.

(If you would /ever/ login, I would have sent this 
in an email! ^_~ )

Kitt