People don't understand why semiconductor argon, and neon can't be substituted by argon, and neon used in welding.
It's very hard to purify noble gasses, as they are almost completely chemically inert, and chemistry needed to make, say, same argon, to form compounds with anything else is something needing very special equipment, and know how.
Welding grade argon is dirt cheap, 99.999% argon is very expensive, and 99.999999% argon is many times as expensive as welding gas.
It's much worse with neon.
