built b16a

i have a 2007 Honda element, and its anxiously waiting for a double din GPS head unit. after visiting a few forums, and asking a lot of questions, i understand the F series are less than satisfying. ive been recommended the D3 by countless members. whats a fair price.. say ebay, brand new? its a private seller, so i assume no warranty. there's one D3 starting at 500, and buy it now for 700. i doubt it will go for 500 flat, with only 1 bidder, but is 500-600 new a fair ball park?