As was said by Opel you're only looking at the surface condition. The work required for the underdash, wheel arch and A pillar is major, major stuff. You could patch it for $1-2K but you wont get someone to fix it correctly for that. Mr Rust will pay you a visit again soon. Have a look in some of the project shots (Pigdogs are good) will show you whats hidden underneath.

Alternatively if you look around hard enough for long enough 2k will buy you a much better unit (mega thorough inspection) and you'll have lots of spares too.

Good luck

So, the POR15....do you get that at a regular parts store or would you need to go through a paint/body shop supply store. And is POR a brand name?
I may need to follow your idea for my sill also...good stuff

Yeah anything is fixable but there is a point at which we can realize if i do this im never going to sell it cause i will never get back what i spent. Then you gotta decide will i or Won't i ? keep it that is. Rust is like cancer it can pop up somewhere else. You would really need to do a bare metal job on the whole car and when done keep it dry stored as much as possible. Will be listing a sedan for sale soon it has 2 semi bad bits of rust one spot in a door (Cut out ready to tidy and weld up) the other in passenger wheel arch.