I'd pay $3k for it and spend a grand for materials: steel, flap wheels, and grinding wheels, grind all the rust away, cut bad spots out and weld in new steel, then flap wheel the whole thing and paint it.
You're in FLA and you have what looks like the rust belt attitude. Maybe you fixed a frame or two of Jeeps driven in the waves to get that attitude, but I think you may need a couple more under your belt.
Of course since that Jeep is in the actual rust belt, they will ask whatever they want for it.
Even though I'm also in the actual rust belt and ain't scared of SOME rust:
Probably followed by:
And a couple days later:
I mean, I know what it's worth to me and how much work would be involved in making me worry less about rust/rot in the long run...or at least what I think would be necessary to fix it.
But if someone pays $6-7k for that? Eh, more power to 'em.