Honestly, anything you spend on that PC is a waste. You can get a 5 year old computer for under $100 and move your updated parts over.
Search Amazon for a Lenovo Thinkcentre, Dell optiplex or anything with an Intel Core i7-4770. This is by far the cheapest route.
Alternatively, if you are looking for the adventure of getting back into PC building, check out the build guides at pcpartpicker.com.
Hey, Terry, I did it! I did my first desk pop!