At least that's how stocks work. If something will be in high demand/price in the future, it will shift and be in high demand now.
It's like other "mined" raw materials.
Coal takes millions of years to form, requires large quantities of vegetation/animal life and large areas of land. If you charged based on replacement cost then coal prices would be effectively infinite.
As with helium. Helium doesn't bond with other atoms to make heavier molecules and so eventually leaks from the atmosphere after release. In order to recover a supply you're going to need to capture it from radioactive decay or do extraterrestrial mining or some similar high cost activity. So it's [comparatively] an infinite replacement cost. However, it's released as a by-product and we currently have enough. When we run out of natural gas sources we'll run out of our main He source too and using helium will become extremely expensive. Even at that point we'll still not be paying the "replacement" cost, just the cost of extracting from more expensive sources.
We should be, as a race, preserving helium but there is currently no economic incentive, the incentive lies in the future when our current round of magnates and politicians will likely be dead.
One of my first jobs was working in a welding supply shop, and I was astonished to find out that a '100lb' cylinder (they're filled by weight/pressure) of helium was nearly $200. As a comparison, a '100lb'of propane was only about $40.
By number of atoms, it is much more (a factor of 10 or so).
I presume the leakage loss in storage also raises the price of Helium. People buy propane just-in-case knowing they can store it forever while helium is a "buy it before you use it" kind of thing.
Are speculators already doing this, driving up the price?
Most of the standard cylinders are fairly secure.
A lot of the time I spent during my job there was preparing cylinders for testing, to assure that they were pressure-secure and airtight. Neat stuff, and a TON of practical physics went into everyday things there. :)
Trying to do the same for small amounts of helium collected here and there is possible but not economically feasible. It makes more sense to use it as balloon gas.
The price of Tuna is set of "how expensive is it to produce a can of tuna" rather than "how many tuna are left in the ocean". In fact, the lower the production cost of tuna fishing, the higher the risk that we empty the ocean of all the tuna.
It's really a problem of the Tragedy of the commons. There is no cost of tuna in the ocean, except the cost of fishing it. So it's a commons, and it will be overexploited.
http://en.wikipedia.org/wiki/Tragedy_of_the_commons
also: be sure to understand http://en.wikipedia.org/wiki/Collapse_of_the_Atlantic_northw...
http://www.thekitchn.com/use-caution-when-eating-escola-6660...
It really seems like the FDA or FTC should be able to regulate that a little bit.
If I sell fruit but I get it by stealing it from a neighbour then I'll be able to afford to sell the fruit at a far lower cost than the cost of manufacture and still get a profit.
The problem comes when the threshold is reached and passed. That is specifically the tragedy of the commons. It's a fractal problem - i.e., even if one country fixes the issue through regulation/taxes/prohibition, another country may still overfish a shared body of water.
The "full cost" wouldn't need to be replacing each fish caught. It would be a fee/tax to ensure a sustainable fish population - this could still result a reasonable market for fish.
In the past we fished at sustainable levels because we were incapable of fishing to extinction. WWF (http://wwf.panda.org/about_our_earth/blue_planet/problems/pr...) say we're taking 2-3 times the volume of fish from the oceans as is sustainable.