If it deployed, then the whole airbag system needs to be serviced, that is pretty pricey from what i have heard, but you may be able to shop around for someone to get it serviced.
There is usually the switch up front somewhere, then there's an air canister that uses some special gas in it, and of course the airbag setup in the wheel.
I used to drive tow trucks, and whenever i'd pick up a car with the bag deployed and deliver it to dealers or body shops, they'd usually total out the car, i guess also depending on the amount of damage caused. if it was not much in your case, and all body damage was fixed by you, then you may get away with it on the cheaper side.
Check with body shops, the dealer on having it "serviced" is all i can say about it.
You probably could just reinstall a new steering wheel with the bag setup in it, but naturally it wouldn't deploy if it was in another frontal collision.