There are other bottlenecks to consider, is your CPU fast enough, do you have enough RAM, could the hard drive your software and OS is on use an upgrade, etc.
If your swapfile is stored on a SSD, how much does it still matter that you ran out of RAM? And if you're not asking your CPU to do as many I/O waits, maybe you can squeeze more useful cycles and therefore performance out of it. A SSD should be a sure way to improve system performance... a reasonable way to spend $300.
Real programs don't eat cache.