S13 Rust Questions

[apex128]

Hi guys,

I'm looking into buying an s13, but it has some frame rust.
How much do you think it would cost to get the rear floor pan replaced (or just fixed) as well as the right frame rail patched? I found a kit from xcessive engineering for about 200 bucks that includes two frame rail covers that need to be welded on. How much would it cost a shop to fix this stuff? I've attached a picture of the rust where the floor pan is becoming detached. I'm mostly concerned with the floor pan as it is loose.
Why do I have to live in Chicago?

Thanks,
Evan