first do a carfax on it.check steering knuckles ,differentials ,sample transmission fluid,brakes.i found a 91 from a customer of mine with 189000 miles on it.it looked like new,inside and out.i stole it for $2900.i put another $2000 in it for mechanical items to bring it up to where i felt it should last at least another 100000 miles.assuming it does it would have only cost me 4.9 cents a mile.if transmission or engine has problems it will be very expensive to fix.i love mine and feel comfortable with my investment.who can afford to pay sales tax on something new,not me!!good luck
do the usual "interview" type stuff, as well...what have they done, how recently, receipts all that jazz. Also, try to figure out if anyone else is looking at it. Then, if you're comfortable, offer around $3000...why not shoot for the moon. Thats your starting point for negotiations. Work to deduct $$ for all sorts of stuff, and get that ride!
i see you are in the austin area - i am pretty sure that is my moms old truck - she bought it new in '91 and traded in in on another 80 in '95 & got real close to what she paid for it orginally (sticker prices really sky-rocketed from '91 to '95). hard to tell from the pics but it was the only one i have seen around austin (or anywhere) with headlight washers and champagne color with a funky dark brown 'pinstriping' / stickers on the rocker panels?!