Another part of the "best weapon for you" equation is use. As you use a weapon your skill goes up in it.

So the best advice to conserve materials is to not build a weapon or gear you won't use.
That said though you do want a variety of damage types at your disposal for different situations so you just don't want to stick to one thing.

Mix things up and have fun, the game isn't difficult enough to need to min/max builds or anything.