A single modern MRI or NMR machine at most would lose a litre per day. The issue with Helium is that the US decided to sell off all its stock (90%+ of the world supply) by 2015. That drove the price right down. If there were restrictions, I once read (YMMV) that a single balloon should cost £150 or so. Bring on fusion quick. Then we'll have too much of the stuff.