Around here, I'm in San Jose, I see them around $3000 -$5000. That's a running truck which hasn't gotten hacked to death or attacked with the rust monster.
I'd recommend learning what mods are good ones, the ones you might do, like master cylinder upgrade, 235 engine swap etc. Shop around so you have some idea of the potential costs, (gauge replacements, upholstery, tires) That way you have some info on your side when shopping.
The other thing to consider; get a 3/4 or a 1 ton. From my experience they can come cheaper as they aren't the rodder's choice! I picked up a great 1 ton for less than half of what it would have sold for if it was a 1/2 ton.
Jeremy