How tricky is this to repair?

Anyone tackled this before?  Interested to know if it is straightforward before I pursue a purchase any further?

Repair panel can be purchased although I'm thinking it's a big job.but fun with grinder

Depends how keen you are!

looks like its been repaired once before but not painted over / protected properly, personally i would easily take that on and use it as a excuse to buy a AC/DC Tig.

Depending on the depth of that rust - With a cheap Mig + grinder and a bit of practice it should be easy enough.

If you are not any good at welding just remember - A grinder and paint will make you the welder you aint!