I’ve played many fantasy role playing games in my life (Ultima, Baldur’s Gate, Dragon Age, etc.) and they all have a concept of magic power, spell points or spells memorized. In these games, mana gives you the ability to cast spells that perform some sort of effect. Once the mana is used up, your wizard is more or less powerless until the mana replenishes.
Growing up I had a concept of money that it was for greedy people or people with motives that were not unscrupulous. It’s only been the last several years that I’ve really come to a more correct understanding of money. Money represents the amount of effort needed to accomplish something.
Need to rake up some leaves? The neighborhood kids might do that for 10 USD. How about magically making a TV appear on your doorstep? Amazon will do that for several hundred USD. Need to build a death star? That will cost a lot more. The link points to an article with a rough guess of 13,000 times the entire worlds GDP as of 2012. Think about that. It would take 13,000 copies OF OUR ENTIRE HUMAN RACE to build one death star.
Certain spells are more valuable than others certainly, which is why a talented, experienced software engineer or a surgeon can make really good money, where a janitor is usually going to be stuck towards the bottom of the pay scale.
Humanity has a way of making things cheaper, and I believe we have a bright future as technological progress allows everything to become cheaper, more accessible and easier to use. At some point, humanity may be able to build a death star or other work that only seems like science fiction right now. Here’s to the future where we are all more efficient wizards.