In my opinion. This is how I judge what I buy and how I buy it.
First off is budget, if you can afford new, quality equipment with warranties, or you plan on keeping it for a long time, buy it. In the long run you will be more satisfied and have less worries/stress if anything were to go wrong.
Second, Buying a factory refurbished item tends to do just fine, however you have to understand that at one time it was malfunctioning and depending on the repair there is always a risk of it happening again.
Third is buying used. if you buy used you can almost enjoy this hobby without putting a dent in your wallet. Now when I say this most products lose about half their value being used over new. But also when you go to resell a used product its still in used shape. Factor things in like cosmetics etc, the value doesn't depreciate as much. Sometimes you can even come out on top if you get a great deal. In most cases however you might buy an ampo for 250 and be able to sell for200, only losing 50 bucks meanwhile be able to enjoy for the period of time you do have it.
Me personally I look at it as an investment, However it may not be in cash form, your equipment will always have a value (if kept up).
Out of all my recent systems, the only thing I have "lost" money on was a battery (lost 25 bucks), and a custom made box, which was made for my grandprix specifically and I thew it into a sale along with my BTL. (~50 lost). Meanwhile I made over 200 by selling my amps etc... So overall I did not lose money by having a system.
So in short. If you got the money buy new, if not buy used and keep your options open and youll be able to get great deals.