About a week ago I was selling a Kooba purse on eBay BIN or Best Offer. I received a best offer of $50 from a buyer who has just signed up for eBay and has 0 feedback. A few minutes later I saw the purse had sold- to the same buyer who submitted a best offer. I didn't think anything of it and sent out the invoice. Later I got an email from the buyer asking me why she got an invoice of $200 when she was only supposed to pay $50, and telling me she wouldn't pay until she got an invoice for $50. I wrote her back and told her that I had not accepted her offer of $50 and she had bought the purse for the full $200. Well, I got a nasty email back from her saying that she had assumed that if you submitted an offer and it was the best received, you could click Buy It Now and get it for the offer price (where she got this from, I don't know!) Anyway, after a few back-and-forth emails she decided she couldn't/wouldn't pay $200. Because she's new to eBay, I agreed to open up a mutual agreement dispute and not go through with the sale. When I first opened the dispute she sent me an email asking why I had opened a dispute when we had agreed, even though I explained that it wasn't a bad dispute and all she had to do was accept it. She won't do that! I'm not sure what to do now- I've never had anything like this happen before! I think she has a week to respond but the week's almost up. I just want my fees back. What happens now? Any suggestions?