You haven't even told us what features you need, what you are going to do with your new build, but you want us to pick out the best board board for you. And you seem to think that if it is more expensive, it is better whether you need it or not. Gigabyte and ASUS make excellent boards, now what is it you are looking for in a motherboard?
Those are the best two mobos that u can get. The price doesn't mean that the mobo is the best.
If u see, the Gigabyte is around $280 and have a very similar performance that the ASUS, in that point u don't look for the high price, u go with the best price/performance.