GMC Denali road bike starts wailing

Bearings in themselves arent that expensive [at all] and you could probably spend $5 for a set of new ones, but if the bike has been wailing for a while, you might want to make sure the friction between the bad bearings and the inside walls of the hub and Cone, hasnt ruined the whole build. because if they have then buying an new hub [$20 - 50 depending on the quality] would be a better option. And if you know how to untie everything you could just run your fingers through to check for any uneveness or bumps, otherwise asking a bike repair guy to help could be a just as good option