Helium is expensive in large volumes. >With refined helium price costing around $30 per hundred cubic feet, filling an airship the size of the Goodyear blimp c

Helium is expensive in large volumes. >With refined helium price costing around $30 per hundred cubic feet, filling an airship the size of the Goodyear blimp could cost in the $75,000 range. Filling Lockheed Martin's LMH-1 could cost $390,000 https://undark.org/2016/03/11/how-to-keep-airships-afloat/#:~:text=With%20refined%20helium%20price%20costing,LMH%2D1%20could%20cost%20%24390%2C000 https://undark.org/2016/03/11/how-to-keep-airships-afloat/#:....