Hi, when I send an offer to people watching an item, and they counter, and I accept, there appears to be no method to invoice them other than message and hope. It also appears the item is still available for sale.This seems like a possible fix for eBay to address.

Once you accept the offer the buyer receives a notice that the offer was accepted and to pay. Once paid the seller will get a notice of sold item and instructions to ship. That is how it works for me anyways.