I believe that they are, to have longer flight times the first most inexpensive thing it to have big props, next you will want to have lower amp draw, this means you need higher voltage. MAthmatically higher voltage is the way to go, but in practise there is only a little gained. You may want to look into single blade props
It was really good in theory, and in some situations even in practise. But when bigger motors came around it reduced the efficiency of a single bladed prop, and they were as you can imagine harder to manufacture, so you will only see them in the RC world not. I am not saying you should go this route, just laying the option in front of you.
If I had some weights pre-made, it would be a good way to reuse broken props hahaha