You can get the Asus N66U for about 115 dollars.
It support both 2.4 and 5GHz, is dd-wrt compatible, the coverage is great, I have 2 laptops, 1 TV, 3 phones and also a PS4 and the signal is stable.
As for speed performance the Asus is one of the fastest routers for a price bellow 200 dollars.