Honestly, I would not put any more money into your system. It would be like throwing good money after bad because that RAM will be useless for you when you upgrade and it will be harder to sell on the used market because everyone is going with DDR4 now.
The 8gb of RAM you have now is fine. It will meet the minimum requirements of just about every game, where your CPU will not. I would save that money for a new CPU/Mobo/RAM.
You might want to consider selling your 470. The 470 has some very good prices right now and I bet you will get more for it than you paid for it. You could get a 1050ti and use the extra money left over for the CPU/Mobo/RAM