upgrading low end to high end

Solution
the i3 is way better than the fx in just gaming in games that use more than 4 threads the fx wins but there isnt many yet to consider it better so i3 is the way to go also this i3 has a .2 ghz increase for the same price as the other i3 so i suggest getting this one

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i3-4150 3.5GHz Dual-Core Processor ($103.99 @ SuperBiiz)
Total: $103.99
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-05-13 04:13 EDT-0400
the i3 is way better than the fx in just gaming in games that use more than 4 threads the fx wins but there isnt many yet to consider it better so i3 is the way to go also this i3 has a .2 ghz increase for the same price as the other i3 so i suggest getting this one

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i3-4150 3.5GHz Dual-Core Processor ($103.99 @ SuperBiiz)
Total: $103.99
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-05-13 04:13 EDT-0400
 
Solution
depend on your budget I3 and fx total different ark for older game I3 have stronger cores so I3 wins newer games which optimize for multicores FX wins you should never go below 4 core to play newer games