Most likely the seller will send you an invoice within a day or so. If they do not you can go to My Ebay and there should be an option next to the item that says Request total from seller . Once you receive the invoice you can click the link that comes in your email to pay, just like if you had won on auction.I doubt the seller can change the price as all of this would have been documented by ebay.
Making a Best Offer http://pages.ebay.com/help/buy/best-offe��Good luck!
The seller will bill you.
