Welcome to the board.
Used gear can be a great option, those who make comments about it being "life support equipment" so you should never buy used quite frankly have no clue what they are talking about. Regulators have changed little in the last 30+ years. All of them on the market today are well made and will give you solid performance. What they do not realize we ALL dive used equipment on every dive, the only issue is who dove it last, them or a stranger. Dive regulators are not some delicate, easily worn out piece of equipment, actually they are quite robust and can take a lot of neglect before failing and age has little to do with performance. There are plenty of 30, 40 and even 50 yo regs still working as good as new. The key is having the reg serviced by a competent reg tech. A service done properly replaces all the internal parts that wear or age, the parts that remain rarely break and if kept corrosion free will last the lifetime of several diver.
Another statement you will hear is "buy the best quality you can afford, don't buy cheap". There is a nugget of truth to that but it is not quite as simple as just buying the most expensive one you can find. The truth is most high end regs from any manufacturer are internally exactly like their less expensive models with some added bling, stickers and an adjustment or 2 but nothing that effects performance or the life of the reg. Same goes for brands, fact is there are really 3 common first stage designs and 2 seconds stage designs that almost (there are one or 2 odd balls) every manufactures uses, no one is reinventing the wheel. There is little real difference any of the brands. Stick with the mid range reg in any well known brand and you will get a good reg.
SO, if buying used is not a bad thing, there are a couple of things you should consider. While from a design standpoint brand name is not important, I do feel it is from a service one. Many of the old regs will work fine IF you can get them serviced and this becomes the key to picking a good used reg. For a first reg, pick a well know brand that has a long history. All Scubapro regs (that I am aware of) and the majority of Aqualung (aka US Divers) except for the really old ones are still easy to get serviced. Most of the other well know brands can also be serviced fairly easily but make sure you have a service shop near you before buying a reg. Go on line and search the on line web sites, if you cant find the brand currently being sold by a good number of dealers, avoid that brand. Dacor is a prime example, there are lots of them around but almost impossible to get serviced. If possible, have the reg given a quick check by a tech. They can give you a reasonable evaluation in a few minutes although plan on having the reg serviced after you buy it, another $100+/- so include that when considering the cost of the reg. Obviously this is not required of a new reg but it will be after the first year so it is only a consideration for the first year of service, if you are getting the reg for ½ or less of its original cost, the extra service cost is made up for quite quickly.
BCs are a little more simple. If it is not worn out (fading is OK) or broke ,it will hold air for at least an hour when inflated (do not over inflate ) and all the inflators and dumps work then there is little else to go wrong. Used BCs can be had very inexpensively. Dump valves and inflators on MOST BCs are easily replaceable so a slightly leaking one is not an automatic no sale, many leaking ones just need a simple cleaning. Again, a quick check by a good tech can help you decide
Bottom line is used gear can be a great deal if the price is right and you can find local service. The simple fact that the gear is a few years old or not the latest and greatest is unimportant as long as its well maintained .
