Processor upgrade

[Frantisek]

Hello, do you think this upgrade will be worth it?
I have no experience with upgrading PCs except for changing memory and reinstalling Windows on a new SSD. I think I wouldn't manage to put all cables together again, so PSU upgrade is not an option  

 

Intel Celetron G530 processor
4GB RAM (1066 MHz for some reason, it cannot go higher even though it's supposed to be 1600 MHz)

256 GB SSD, 1 TB HDD

no graphics card, motherboard has 2 slots, but the PSU doesn't even have additional power connector... I don't want things to fry when I plug something in (I thought about GTX 750 ti, but chose not to risk)
1366x768 monitor

I want to change the processor which is probably the biggest bottleneck. Do you think i3-3245 is better? Will it help in gaming? Our family shares that PC and it's so frustrating to play World of Tanks at 20 FPS at minimum graphics.
When I looked at this comparison, I found out that graphics base frequency is actually higher on the Celetron G530. But is higher frequency always better? http://ark.intel.com/compare/74746,53414

Please, help me decide what to do  

 

[The Sloth]

save up, get a old OEM PC with i7 3770 

[Blebekblebek]

1. Sandy bridge only support 1066Mhz RAM

2. if budget is a problem i5-2400/2500 would do the job, or i7 2600 (non-k version), because I don't think your motherboard support Ivy Bridge or Overclocking at all just like most OEM computer.

3. 750Ti for this build is very reasonable.

Forget i3, because with $5 more you can get i5.