Opinions on rust repair

here's what I'm dealing with: I have a guy that will repair both my quarter panels and paint for 400 flat. I bought the car for 1300 and plan on keeping it for a long time, since there is nothing mechanically wrong. Does this sound like a plan? I am planning on doing it but my stepdad doesn't seem to think it is worth it. Here's the damage:
it's worse than in this picture and on the other side too.
let me know, Thanks!!

it's worse than in this picture and on the other side too.
let me know, Thanks!!