27″ Acer XF270HU WQHD Widescreen 2560×1440 144Hz IPS FreeSync Gaming Monitor $399 +Tax or S/H at MicroCenter

http://www.microcenter.com/produc…-_FreeSync
MicroCenter has Acer XF270HU on sale for $400
This is one of the few(maybe the only one) 27" IPS monitor that can do 23-144hz FreeSync on the market.
Amazon Reference