I know there's another big monitor deal going on at the moment but this was the best priced 28" 4K G-Sync monitor I could find.
Best price on static ice is $649, although I've found it a bit cheaper elsewhere.
Item specifics
Condition:
Brand New: A brand-new, unused, unopened, undamaged item in its original packaging (where packaging is … Read more
Display Technology: LED LCD
Response Time: 1ms
Brand: Acer
Model: XB280HK
Contrast Ratio: 1000:1
MPN: UM.PB0SA.002-D10
Video Inputs: DisplayPort
Screen Size: 28"
Maximum Refresh Rate (Hz): 60
Max. Resolution: 3840x2160
Aspect Ratio: 16:9
Refresh Rate: 60Hz
Features: Security Lock Slot, Anti-Glare, Anti-Static
Brightness: 300cd/m²
With the cashback I think that brings it to $512.71