Refinishing damascus barrels runs roughly $500.00. If you want the lockplates and trigger guard, etc recolored it's probably another $400.00. Before spending any money on the barrels, the wall thickness should be measured at various intervals as well as the bore. If the barrels have severe pitting or the walls are thin, then you have nothing really and spending money would be a lost cause. Even if the barrels check out okay, you will likely spend more than the gun is worth to have it done correctly. Are the barrels on face? Any play in the action? How bad is the wood? Refinished barrels and a well worn looking stock don't match. Any mechanical issues will also be costly. It just depends on your reasons for doing it. If you are thinking for resale to maybe make money, you better think twice.
I have been down this road a few times and I have more into each gun than I will ever see out of them. But resale was not my reason for having them done. Also, expect the unexpected which can quickly reek havoc on your pocket book.
I will be away for the weekend but if you want to shoot me a pm I can go into much more detail when I get back.