I don't believe that Windows should be included in the build cost because it is software and optional.
For the CPU I went with Intel Core i3 6100 it has enough power to play the most intensive game with only minor bottlenecking but luckily it won't have noticeable frameskips if it even will.
For the GPU the RX 480 was an obvious choice providing great performance with a cheap price, showing that it will beat a GTX 1060 if both cards are benched on DX12 games giving large frame deltas
RAM has to be a minimum of 8GB which I went with a single DIMM to allow for upgradeability. Take note if you use this config for RAM you will decrease the board's lifespan which is still practically unnoticeable. put the RAM in XMP and set the voltage to 1.35v to use the ram safely.
For storage, you can either go for a 1TB WD Blue HDD or a 240GB SSD from OCZ for 4 dollars more if speed is your thing.
For the PSU, it is an 80 PLUS Bronze PSU so you can't go wrong with it. 520W is Plenty for a GTX 1080 so no need to go any higher in capacity.
The Case is for me a personal choice i went with the cheapest M-ATX case available but you may choose to go for any case you wish.