Router suggestions

Currently have a nighthawk 6700 with Cox Gigablast. Our WiFi has been struggling recently it seems, & I have tried resetting everything multiple times. Still seem to have a weak signal…like 2 bars, occasionally 3.  The Nighthawk is 2-3yrs old…& I am not very knowledgeable on routers, looking to step up if I purchase a new router…but not trying to go ridiculous price wise.  Any help would be appreciated..