I have a GT Aggressor Pro. And pro it is... at having issues. I am looking to upgrade to something from a better brand like trek or diamondback. I have no idea at all what to get. I have a very small budget of $800 and live out in a very small town where everything is on a hill. Anyways, if I don’t have a spot to use a mountain bike as it should be used (I mainly ride on road with a little gravel) what should I upgrade to? I don’t want a used bike though.