Cheap gaming PC with 1 stick RAM feasible without bottleneck?

Hello,

I'm building an extremely cheap gaming PC. I already have Win7, a case, and a quality PSU.

I'm getting:

MSI H61M-P31 £30
Celeron G530 £30
Radeon 6770 £70
1 * 4GB DDR3 £15

I'm just wondering whether using 1 stick of RAM rather than 2 is going to bottleneck this system with regards gaming in any meaningful way? Baring in mind the Celeron memory controller can run RAM at only 1066mhz.

The reason I'd prefer to buy 1*4GB rather than 2*2GB is because it's cheaper now, and also easier/cheaper to upgrade it in the future.

Let me know your thoughts!