The build below far surpasses the one in the original post in processing power. It has an i5 instead of an i7, but if the purpose of this machine is just gaming then this is perfect. If he will be using it primarily for things like photo-editing and recording gameplay and streaming it, or other things of the sort, then an i7 would do him a better service, but this build is an incredibly powerful gaming machine. Just so you know, the processor and motherboard cannot overclock, but at stock settings this cpu can still crush practically any game on the market with the right graphics card to back it up. With this build, you'll be sitting pretty with settings maxed out at 1080p for years to come.
However, if you can convince your friend to get a slightly cheaper mechanical keyboard and a simple 250gb SSD with a 2TB HDD, you'd both save enough money to afford an i7 that can oc (with a matching motherboard), but you might even have saved more money in the end. SSDs are great, but price/performance? I'm not really sure a 1TB SSD is worth the price at this point in time. In a year or two it definitely will be, but they can be pretty expensive. All I'm saying is that his budget could be better allocated to processing power, but if that's not what he wants, then it's up to him. SSDs are great, so at least he'll have fast load times.
PCPartPicker part list:
http://pcpartpicker.com/p/C8VPbv
Price breakdown by merchant: http://pcpartpicker.com/p/C8VPbv/by_merchant/
CPU: Intel Core i5-6600 3.3GHz Quad-Core Processor ($215.99 @ SuperBiiz)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($24.89 @ OutletPC)
Motherboard: Gigabyte GA-H170-GAMING 3 ATX LGA1151 Motherboard ($84.99 @ Newegg)
Memory: G.Skill NT Series 16GB (2 x 8GB) DDR4-2133 Memory ($55.99 @ Newegg)
Storage: Mushkin Reactor 1TB 2.5" Solid State Drive ($209.99 @ Newegg)
Video Card: EVGA GeForce GTX 980 Ti 6GB ACX 2.0+ Video Card ($599.99 @ Amazon)
Case: Enermax ECA3280A-BL ATX Mid Tower Case ($73.99 @ Directron)
Power Supply: EVGA SuperNOVA G2 550W 80+ Gold Certified Fully-Modular ATX Power Supply ($83.99 @ SuperBiiz)
Optical Drive: Asus DRW-24B1ST/BLK/B/AS DVD/CD Writer ($18.89 @ OutletPC)
Case Fan: Rosewill RFA-120-BL 74.5 CFM 120mm Fan ($7.89 @ OutletPC)
Monitor: Acer H236HLbid 60Hz 23.0" Monitor ($119.99 @ Best Buy)
Keyboard: Corsair STRAFE Wired Gaming Keyboard ($89.99 @ Amazon)
Total: $1586.58
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-04-10 19:15 EDT-0400