How much should i offer for this truck?

This guy told me to make an offer but i dont know how much i should offer or hoiw much is too much i know i like the truck and i want it so please help. its a 1997 chevy 1500 standard cab stepside bed red with no cosmetic damage its 2 wheel drive 5 speed 305 motor and 102000 miles no tears or stains on seats. no bedliner tho. so from that info what would you offer?