eBay formally announced a forthcoming feature that allows potential buyers to make sellers an offer on fixed-price listings, including Store inventory listings.
Unlike a similar service from Yldfire that was forced off eBay, eBay's Best Offer feature does not allow sellers to automatically reject offers below a certain amount to help automate the process. Buyers are allowed to make one offer per item in most categories, and are allowed to make three offers in the Business & Industrial category and 10 offers in the eBay Motors marketplace. eBay's Frequently Asked Questions about Best Offer says sellers can ignore or bulk-decline offers considered too low.
The feature, to be made available this week, is optional for sellers. When a seller chooses to accept offers on a listing, a "Submit Best Offer" link will appear below the Buy It Now button on the item page.
http://www2.ebay.com:80/aw/marketing.shtml#2005-01-21091814