Display Enlightment by NCX

How much is a new Samsung versus AOC?  If PC gaming with a Free-Sync compatible graphics card the AOC is probably the better choice since it supports Free-Sync and 75hz, though the Samsung can probably overclocked to 71-75hz, has a height adjust-able stand, better image quality and is faster.  I can not recommend second hand monitors without knowing where they come from and what condition they come in.

The Samsung is about 198 USD while the AOC is 137 USD. The used Samsung one is 101 USD

Im also considering the AOC I2490VXQ and BenQ GW2480. Which one is the best, the BenQ GW2480, 24v2Q or the I2490VXQ?
http://bestmonitorsbyncx.createaforum.com/general-discussion/best-24-25%27-1080p-ipspls-monitors/?message=111
http://bestmonitorsbyncx.createaforum.com/general-discussion/best-24-25%27-1080p-ipspls-monitors/?message=113