Seems like a good price for a 144hz monitor. Checked on camelcamelcamel and it has been this price before but never cheaper.
Bit of blurb
The Acer Predator GN246HL is 24-inch LED monitor to support NVIDIA 3D LightBoost technology and NVIDIA Vision two kit (sold seperately), delivering brighter Full HD 3D imagery via PC DVI-DL. The 1 ms response time and the refresh rate at 144 Hz, make it optimal monitor for high speed games.