We had a pretty bad hailstorm a while back here in E.TN/SW.VA...windows, roofs, cars,trucks,barns, everything got smacked. Area was declared a disaster so insurance companies (the good ones) started paying off quick.
Now the bad side: Every Tom,Dick & Harry opened up a "Paintless Hail Damage Repair" shop. These guys swooped into the area like locusts, got to be you couldn't sling a dead cat without hitting somebody wanting to fix your dings.
How much will it cost? That depends on your vehicle and its insurance rating. One dent in a Lexus may cost the same as 50 in a Geo Metro.
Make sure you use someone reputable, ask them how they are going to repair the dent. Avoid the "dry ice" guys, yeah it'll pull out small dings but, from what I've been told, when your car's surface heats up in the summer you'll notice the paint is separating from the metal too.
I'd consider somebody local (repairshop/dealership/etc) that way if you have trouble, at least you have somebody to go back to for help.