I mean, I hope you understand replacements would have to be welded in right? I was disappointed when I first learned the quarters, the FIRST thing that rusts out on hondas, are a part of cars that is welded in. Even so, repair is not completely outrageous if you shop around. Or, you can be really brave and just give it a go, I mean, it's already rusted out, you're only going to make it look better. The beauty of body work is that the tools and materials are painfully expensive to buy (save for the paint supplies). Just get a sander, bondo, sandpaper, a body work hammer, and get to work. Watch some videos online first to get a knowledge base and then develop a feel. Of course the rule of thumb is start small, don't go crazy just pasting bondo on all over.
Or, if you have a few hundred dollars to spare, just pay someone else to do it. Building that skill would only pay off if you intend to pick up money doing it in the future for someone else, or if you find you buy a lot of cars that are in that price range where rust is always part of the deal.