Agreed. See if your board can support the Q88xx chips or Q9550 and search around (ebay, Amazon, google etc) and install one of those if you want something cheap. Also a good option is a FX4100 for 99 dollars. You can see deals like this all the time, and this is good enough to play BF3, combined with a 6870 (now 179) should be pretty good on a budget.http://www.memoryexpress.com/Products/BDL_FX4100_970AD3
I had a E8500 Dual Core and noticed that performance hit with a 4870 in BF Bad Company 2 - Purchased a Q9550 before they phased them out and its been no looking back.
Most games now will need at least a Quad around 2.83-3.2 GHZ(recommended). That FX4100 chip is super cheap with the MB, You won't beat that price per performance ever. Its Almost as fast as the Q9550. If you spend the extra for a 6100 (6 core) it'll last even longer. Point is a budget to get what you want. a good playing experience.
With a combination above, you would be able to achieve high detail with 1400*900 or 1600*900. That 6870 surprised me with Max Payne 3 as well, Ran smooth at 1080p with the CPU at stock speeds ( i only overclock if i need to )
I snapped a 6950 (2 GB) on a special - As games are now requiring 1 GB to play at the recommended spec.