Tips on buying a used car, regarding price please?

im looking at buying an integra, i'll meet teh seller on friday, hes asking 3.4k but KBB values it at 2.5k max. Can i trust kbb? i dont want to look like a cheapa** when i go there. Or will i look educated becasue i know what its really worth? what are some other sites that i can get values for tegs on?|||auto trader.ca