Looks like it's still on the store but no "buy" button http://store.acer.com/store/aceramer/en_US/pd/ThemeID.35703000/productID.314151300
Quote from Acer website when you hit enter in the qty field
We're sorry but XB270HU BPRZ WQHD with NVIDIA G-SYNC is currently out of stock and cannot be added to your cart. We apologize for any inconvenience.