It's quite sad and ironic, we're using up the supplies on party balloons.
As for why it's cheap and still considered threatened, I believe there was a big stockpile that got dumped on the market at some point, and we're still filling up the party balloons from it - but in a decade or two the party will be over.
Found it: http://www.independent.co.uk/news/science/a-ballooning-problem-the-great-helium-shortage-8439108.html
But 2015 has passed, and Helium is still cheap.
That article also contradicts itself quite a bit, complaining that Helium is too cheap, still having case stories about facilities shut down due to problems sourcing Helium at reasonable prices. Weird.
Yes super weird. For me, the article pursues a double purpose, even if I emphasize a bit the problem still does not break it down correctly. And another thing is if the USA really gave their reserves in helium made a very bad move
I read a bit more on it.
This reserve storage was leaking, and it was costly to maintain, particularly the latter point drove the decision to sell off the helium.
If I understand it right, it's not that super-trivial to just take the helium out of the storage - it has to be tapped at constant rate, so it's totally unsuitable as a buffer. It's also nearly empty, with the tapping rate being much lower than when they started selling off helium.
Helium is notoriously difficult to store, this causes a quite inelastic market situation and can explain that there are temporary outages in the same time as there generally is a glut in the market. However, googling for helium price charts, I didn't find much volatility. Prices have steadily been rising over the years.
Yes, in fact, one of the main storage methods is to combine it in tanks with 20% oxygen. But it has great limitations.
You can check this article.
http://assisted-dying.org/blog/2015/04/24/australian-warning-on-diluted-helium-tanks/
As I understand the quoted article, they've started selling party balloon helium in the Australia with 20% added oxygen in order to prevent deaths from people inhaling the helium (either as a party trick getting squeeky voices, or as a means of suicide). The article recommends anyone planning to suicide by helium inhalation to check that their helium doesn't contain significant amounts of oxygen.
Certainly it is possible, now there are many clashes over natural resources. Now imagine that these natural resources are depleted and helium is the most demanded, certainly that would cause many conflicts