There is nothing wrong with buying used gear. You can save a ton of money. Vintage equipment always is bought used.
Just because something is old doesn't mean it doesn't sound good. Buyer beware on e-bay. You can get good deals there, but use your head. Especially when dealing with a music store. They are not there to loose money.
Most all of my gear is used. The only things that I have bought brand spanking new is my new guitar and amp, and my Kurzweil piano.
When I had my last studio set-up four years ago I used a DBX 262. Well they don't make that anymore, but I liked it so much and it sounded so good I searched for a used one. I found one for $90 bucks and it looked brand new. Works like brand new too.