I like 13-inch laptops/help me find one

I like 13 inch laptops. The screen is not too small to be unusable yet is not too large that it is a pain to transport. However, the PC industry has seemed to have overlooked this and now a majority of laptops on the market today are 15.6 inches instead. The few 13-inchers that do exsist are very expensive. I need to find a 13 inch laptop that is cheap and fast enough. This seems to be a problem for me; can anyone reccomend a good 13 inch laptop that is

1: Under 500 dollars

2: Has eather an intel i5 or AMD A6 processor

Help me out here! So far I have found a good supply of used 13 inch macbook pros coming from cregslist. However I do not think that the core 2 duo chip will be enough.