Nah, one MRI magnet uses more helium than 10,000 kids balloons, and you get to charge $5,000 every time you use it.

Uses or wastes? I.e. is 10k-balloon-equivalent helium released or reused?

Reused unless you do a quench (emergency shutdown)

This comment led me to: https://www.youtube.com/watch?v=9SOUJP5dFEg

Apparently helium balloons use only about 8% of the annual consumption of helium, and that's just about the highest-margin use there is--hospitals effectively pay less for their helium because it's subsidized by kiddie balloons.

It is an entirely fanciful notion that the cost of helium would ever be high enough that going to the moon to retrieve it would be economically viable.