well check this out. I own a lanzar vibe 1800d (1200-1400w rms amp) bought it for 140$ factory refurbished with warranty. Amp lasted a year, after it broke. I don0t have warranty anymore but they told me to send it and they will change it for a new one or they will put new components all over the board and return it to me. For 140$ i can't argue!!
my point is, try getting refurbs from good brands or brands with good service.
I have never bought a referb, but i fried my Tsunami DB1100d and i sent it in to get refurbished and it has worked flawlessly since i have gotten it back....i'd say if its refurbed by the company who made it and it is a respectable company..i'd buy it