A few months ago I purchased a new regulator and octopus because… well… it was time for a change. My old ones, a Mares Abyss MR22 regulator and octopus have held up well over the past few years, but I purchased them from a friend (used) when I first started diving and besides I was already Pro-Dealing a few other things.
The manual says the Abyss MR22 was designed for a “2 year or 200 dives” service interval. (Note: Other regulators and manufacturers have different service intervals.) Now that I’m getting ready to sell it, it’s probably as good of a time as any to get it serviced again. Maybe I’ll even get a higher price!
Generally I take my gear to Sports Chalet (it’s my dive shop) when it needs to be serviced, but any reputable dive shop should be able to take care of it. Getting paperwork as proof never hurts either.