nothing wrong with ebay, just dont buy the cheap rubbish.
i will repeat ebay is fine for used highend cctv gear, thats why i have approx 10 grands worth of high end branded cctv gear, that only cost a fraction of that buying it used on ebay, and none of it has arrived doa, and continues to work to this day
panasonic
dedicated micros
dennard
vista
honeywell
pelco
buy any of the above used to have the same gear used in highend pro installs
you can even get brand new of the above for upto 80% off the normal price, all you have to do is look and bide your time and wait for the bargins.
You will find allot of wholesalers stick end of line stock on ebay. I stick second hand gear on it, like now I have 3 lots running for kit nothing wrong with it all working. A client wanted some new stuff in so I took it away and its now on ebay. Hunters and CCTV uk have ebay accounts.
As long as you buy smart nothing wrong with ebay.