If it's mechanically sound it may be worth the money, especially here on the east coast. I'd pay 1000 for that if it was a good running truck. Heck I paid 4000 for my first rust bucket. The rear shocks member fell of the truck while crossing the gw bridge one day.
Kinda what im doing.... rebuilding my $1000 cruiser with 500,000kms.
Figured if I had to buy the roof rack that came on it new, I would have paid $1K for the rack alone. But with that said it is turning into a big project to get baselined and reliable, even though it was 'fully operational' when I bought it.
Im over 10K into her now. Almost done for now.... This has been budgeted over more than a year and so becomes much easier on the pocket book than a 10-$15,000 single purchase. Other big benefit is knowledge of your truck inside and out. Not to mention the satisfaction of repairing, and knowledge of exactly what (and what has not) been done.
All that being said, that rear end is fixable but nasty job. Bondo and rust are all over these things and can eat money and time like ive never seen before. So if mechanically sound, I would cautiously pursue the $1000 cruiser expecting to sink much time and money into it to become reliable.
Those two vertical holes in the C-channel are for the swaybar (prevenst sideways hanging in corners) and that rust just let it be, paint with rust primer as it looks like paper but is rock hard stuff, the rivets are a pain to remove.
The shock-tube might need replacement, the rust in panels is doable if you have time and a welder and some happiness doing it.
The fun stuff is adding some things that make it your truck like roofrack, lockers, winch...
Just spend about 2000 on new parts like brakes, tires, suspension and worn out parts like axle shaft spider gear, exhaust, bearings, birfields, filters, fluids: there is so much but you might want to check the cylinder pressure to see how much worn out it is.
(or do a rebuild of the engine)
Seen worse on MUD and in person. Probably not an ideal candidate for "restoration" as has been mentioned, but you could patch it up if/when it comes to it as long as you're not concerned about it looking pretty or original. Body rust is scarier to me than frame rust. Thick steel is easy to weld on.