Is it safe to assume that equipment being sold by a dive shop has been properly maintained and prepped for resale? If the equipment is working well, why would they sell it? Silly question????
Shops sell off rental equipment periodically because they can purchase new gear at heavily discounted prices. Selling used equipment while it still has a fair amount of value allows the shop to recoup all or most of its initial investment in the gear. If you could sell off your old reg at 50% of the MSRP and then purchase a brand new reg for the same amount (or possibly less), wouldn't you jump at that chance? It's really a no-brainer from the shop's perspective.
As others have mentioned, don't assume anything, particularly with regs. Ask the shop when the reg was originally purchased and how it's been maintained.
I wouldn't buy a used rental reg unless it had just been serviced and was guaranteed to function properly. Servicing for an out-of-warranty reg (which is basically any reg purchased secondhand) can cost $75-$130 including labor + parts, so you don't want to get stuck with that expense until
you've enjoyed using the reg for 2+ years.
BCDs require less attention than regs. It's worth mentioning, however, that if you are going to be shopping for a used BCD or reg,
you should know how to do comprehensive functional checks for the gear. If you don't know what I'm talking about, then you should ask an experienced diver or technician to look over the gear
before purchasing anything.
Are there Brands to stay away from?
I'd recommend sticking with the major scuba manufacturers (Scubapro, Aqualung, Apeks, Atomic Aquatics, Oceanic, Mares, etc.) so that finding replacement parts and getting the gear serviced is not too difficult. Stay away from Dacor regs since finding overhaul kits for the now defunct company is problematic. Buy a brand that you can get serviced locally.
Quality & Budget-Wise computer suggestions?
If you're on a budget, a dive computer that was formerly part of a shop's rental fleet could be a wonderful bargain. Typically, shops will rent out simple computers like the Suunto Gekko, which is a rock-solid performer. It's nitrox-capable, easy to read, easy to operate, uses a conservative algorithm (Suunto RGBM), has a phosphorescent screen (charged up by shining a light on it so it doesn't suck power from the battery), user-replaceable battery, and can be mounted in a console or on a wrist. An unadvertised feature is that, with the proper cable, dive profiles can be downloaded to a desktop/laptop computer. For the PC, this requires a small hack. For the Mac, no hack is required. What's not to like? I'd probably be willing to pay $100 for a used Gekko. The newer version of the Gekko (Suunto Zoop) can be purchased brand new and on sale for a little less than $300.
Is mask and snorkel brand important or just getting a good fit?
Buy the cheapest snorkel you can find. Stay away from expensive ones with "dry" gadgetry on them. I don't take a snorkel with me on most of my dives nowadays. It can get tangled in the long hose for my primary reg. Other divers prefer diving with a snorkel. To each his own, I guess. Most scuba instruction agencies require OW students to dive with a snorkel, so you'll probably have to take one with you during your class dives.
Get a dive mask that fits your face.
