Of a listing?
As mccrimm says, Relist. The cancelled Listing is in your Unsolds.
Of a purchase?
If you and the customer now agree, relist, using his eBay ID as the title and adjusting the asking price and selling price according to the current agreement.
Use Fixed Price /30 Days. Give the customer a reasonable deadline (48 to 96 hours ?).
If he doesn't buy by the deadline, change the title to something searchable. And adjust price and selling if necessary.
The item now is available to anyone who meets your price for most of a month.
