So just to give you a good general idea(not including cables such as Display or SATA cables and other miscellaneous items such as thermal paste/Case Fans), it is a little bit more then $750, and there are cheaper part options.. but this would fit the bill for medium to high at 1080p.
Case/PSU-http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.2129533,
http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.2129533
1080p Monitor-
http://www.newegg.com/Product/Product.aspx?Item=N82E16824260227
AM3+ Mobo-http://www.newegg.com/Product/Product.aspx?Item=N82E16813128514
GPU:GTX 750 Ti-http://www.newegg.com/Product/Product.aspx?Item=N82E16814121896
8GB RAM-http://www.newegg.com/Product/Product.aspx?Item=N82E16820233170
HDD-http://www.newegg.com/Product/Product.aspx?Item=N82E16822236345
CPU-http://www.newegg.com/Product/Product.aspx?Item=N82E16819113286
Windows 7-http://www.newegg.com/Product/Product.aspx?Item=N82E16832416806
Total cost comes to around $808(including OS and Monitor) and like I said before there are other components that may still do what you are wanting, just not quite as well... Hope this gets you in the right direction..