Your CPU is a bit underpowered for gaming, and if you were to upgrade to, say, an i5, you'd also have to upgrade your mobo because an i5 uses LGA 1151, and what you've got right now is AM3, AND if you get a more modern i5, you'd also have to get a set of DDR4. I'd say grab a 1060 (~$220) or 1070 (~$400). An i5 6600k is around $240, and a good LGA 1151 mobo is about $130-150. 16GB DDR4 is about $80. All in all that's about $700 if you went with a 1060 or $900 if you get a 1070.
MY ADVICE: Either wait and buy it all at once or separate it into groups and buy them separately. Sorry if this was a little long