1968 barracuda conv. value? QUICK

i really don't need this car but poping up for sale only minutes from my house, i have to go see it and make an offer. these things are known for rust out back. i just hope i can see it well enough to tell how bad it is rusted. any special order item that would make this more valuable? going to check the vin and see what i can find out. i have my cheat sheet and cash ready to go. hope its not a let down. or worse- i get excited and pay to much for it!