Assuming the headset supports Crossfire, $1500. You need to be able to get a stable 90fps on 2400x1080. 1440p benchmarks are the closest guess, or ultrawide 1080p benchmarks if you can find them. December is far away though, it might get cheaper with new hardware, like the R9 300 series.
PCPartPicker part list / Price breakdown by merchant
| Type | Item | Price |
|---|---|---|
| CPU | Intel Core i7-4790K 4.0GHz Quad-Core Processor | $326.99 @ NCIX US |
| CPU Cooler | Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler | $28.98 @ OutletPC |
| Motherboard | Asus Z97-E ATX LGA1150 Motherboard | $109.61 @ NCIX US |
| Memory | PNY XLR8 8GB (1 x 8GB) DDR3-1600 Memory | $53.98 @ Newegg |
| Storage | PNY XLR8 240GB 2.5" Solid State Drive | $89.34 @ Mwave |
| Storage | Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive | $49.89 @ OutletPC |
| Video Card | PowerColor Radeon R9 290X 4GB PCS+ Video Card (2-Way CrossFire) | $283.98 @ Newegg |
| Video Card | PowerColor Radeon R9 290X 4GB PCS+ Video Card (2-Way CrossFire) | $283.98 @ Newegg |
| Case | NZXT S340 (Black) ATX Mid Tower Case | $67.99 @ SuperBiiz |
| Power Supply | EVGA SuperNOVA 1000G2 1000W 80+ Gold Certified Fully-Modular ATX Power Supply | $109.99 @ Newegg |
| Prices include shipping, taxes, rebates, and discounts | ||
| Total (before mail-in rebates) | $1527.73 | |
| Mail-in rebates | -$123.00 | |
| Total | $1404.73 | |
| Generated by PCPartPicker 2015-03-06 11:11 EST-0500 |