How much should a 2nd hand Intel Arc B580 be?

So I'm looking at a less than 1 year used Battlemage, with Warranty pa but will expire this January and the seller said was only used for mostly Valo and office work (YT, minor Vid editing). How much should I offer them na both fair on both of us since a BN Arc B580 could cost less than 15kph from an official shop?