ayhan 
Best Buy via eBay has 27″ Dell S2716DGR 2560×1440 144Hz G-Sync Gaming Monitor for $299.99. Shipping is free.
Specs:
Resolution: 2560×1440
Refresh Rate: 144Hz
Panel Type: TN
Response Time: 1ms (Fast Mode)
Contrast Ratio: 1000:1
Viewing Angles: 170° (H) / 160° (V)
Inputs:
1x HDMI
1x Display Port
