Well, I'm not for sure about prices. Best thing I can tell you is to shop around, get several estimates...maybe find the parts yourself so you don't get elevated prices...and most of all don't let anybody f*ck you, which is one thing most auto places have in common.
almost same thing happened to mine, at least to the rear panel there--- you can get an aftermarket (or OEM if you want) fender for about $140-$180, then have a paint shop paint it, the price i'm not sure of there, lots of people have different prices--- the rear panel though, I was lucky and mine just popped back out, so hit it from the inside a couple times and see how bad it is... otherwise, yeah that's body work that almost any shop would do but they'd charge you as much as they can for it---- Depending on how much you want to save on insurance, it might be worth it to do it independently from the insurance company--- at least get 2 or 3 estimates from body shops, then you have something to go on--- and most insurance companies like to have 2 or 3 anyway to review before they make the final estimate and cut you a check.
for the front you might be able to get away with banging it out and body filling the rest then prime and paint it, but for the back you may need some professional workor bang it out and do the same, but its not easy work, ice sucks when i slid into the ditch with my s10 i nailed my tailgate but i just bodyfilled it and like 5 coats later (or body fill) it looks pretty damn good
that shot to the back end will probably cost ya...more than the front...there are a couple of new front fenders for s-10 and sonomas on E-Bay for auction...might help ya out on the money issue..with the front...but...the new method for puling panels out is ...taking and tack welding hooks on the panle and pulling the panel....and then just grind the hooks off.....but..i ma not suree....$500..maybe..roughly