As stated above it is your choice. But if you bought the regs new you will receive free parts from most of the name brand manufacturers as long as you service them each year. Service runs around $50-$60 for the set, 1st and 2nd stages and octopus total. You might get a better price but it should not be more. I don’t bother servicing my B.C.D. but even in the event of a critical failure I can dump weight and surface. (OK unless the inflator sticks open and then I can disconnect).
For me, my life is worth more then $60 a year. There is a school of though that if it is working leave it be. I have talked with people who told me their regulators breathed worse when the got them back from repair. Once after having my gear service the first stage came back with what they call creep. Because of an "O" ring which was installed wrong the intermediate pressure (the pressure leaving the first stage on it’s way to the second stage) would increase or creep over time. Find a good repair shop and even then double check the operation of your gear we you get it back.
All this being said, if the regulators were stored in a cool dry place and no water accidentally got into the first stage they are probably safe to dive with. I would at the very least hook them to a tank and breath from both the primary and octopus. Chances are if they breath on the surface they will at least feed you air on a dive.
My rule is before you buy any other scuba gear spend the absolute most you can afford plus another 20% on your regulators and keep them in good working order. In my opinion little does more to ad to your diving enjoyment then and easy breathing high quality regulator.