That price is more than a decade out of date. Helium has been about 10x that the past half decade. I used to pay about $3,000 per 100L dewar a few years ago. Sounds like that price was still common in 2020: https://physicstoday.scitation.org/do/10.1063/PT.6.2.2020060...

Plus, liquid helium is produced as a byproduct of some natural gas extraction. If you needed volumes beyond that production, which seems likely if you wanted to switch the world's data centers to it, you'd be stuck condensing it from the atmosphere, which is far more expensive than collecting it from natural gas. I haven't done the math. I'm curious if someone else has.

That's the cost for one-time use of the helium. If you're running a liquefier the cost is much lower, since you're recycling the helium, but it still "costs" ~400W to cool 1W at 4K.

In other words, the helium is used to move heat around, and isn’t lost. It’s like the refrigerant in your air conditioner, except that it needs several stages of pre-cooling.

Initial cost is high but running it should mostly just incur energy costs if it’s well designed.

Nitrogen is N2, though. Liquid nitrogen is cheaper than liquid hydrogen.

I was able to find "1 gallon of liquid nitrogen costs just $0.5 in the storage tank". That would be about $0.12 per 1L of N2.

Edit: Didn't read the OP carefully... Am idiot. Anyway, maybe someone reads something new to them.

Nitrogen won't get you below 10°K, tho. It's solid below 63°K (-210°C).

You know things are getting expensive, when superconductors are rated "high temperature", when they can be cooled with LN2...

Helium (He2) is _practically finite, as we can't get it from the atmosphere in significant amounts (I think fusion reactor may be a source in the future), and it's critically important for medical imaging (each MRI 35k$/year) and research. You also can really store it long term, which means there are limits to retrieval/recycling, too. I sincerely hope we won't start blowing it away for porn and Instagram.