it really doesn't matter as far a premium vs base, it's more of an aesthetic thing. base rock tends to be less covered in coralline algae and tends to have less "life" as far as the visible stuff goes. the premium rock tends to have more coralline and more growth of various things, and also has more unique shapes.
base rock is supposed to be just that, a base. it's cheap with boring shapes and less life. i'd get quite a bit of base rock to build a nice foundation, then get the more premium stuff to make it look better.
there's no formula for rock really. i'd recommend at least a pound per gallon, but it usually requires more to make the tank look "complete" or "full". you could do all premium rock, but it would be expensive. you could do all base rock, but it won't look as nice.
also realize there is a distinction between base rock and dead/dried out rock. if a piece of rock is dried out, all the life on it is probably dead. if that's the case you would have to get some good live rock to seed the dead rock and make it live again.