Negotiating a sale on eBay?

[Matt]

I am looking to purchase an item and several accessories from one seller on eBay. They are all Buy it Now, not auction items. I messaged the seller through eBay asking for some kind of package deal. The seller agreed and sent me the adjusted prices. Now how do I purchase at these prices? Can the seller change the price on the listing? Or should the seller just send me a Paypal invoice? What's the easiest way for both parties?

[the ox]

The seller would have to make up a special bin ebay listing with a heading like 'For Matt' with the price you have agreed.