Zechstein Magnesium Chloride (Ancient Minerals) -Really the best and only option?

I know the claims about Ancient Minerals' Zechstein sourced oil. I know that Dr. Sircus recommends this brand exclusively. But, at $119 for 64 oz. plus shipping, it's just so expensive. Are there really no quality Magnesium Oil products at lower prices?

The arguments on this forum and other websites state that other Mag Oil made from Ocean Evaporation or Nigari contain unavoidable impurities because of the polluted state of the planet's waters.

Some recommend buying Ancient Minerals Magnesium Flakes and making one's own oil - but then, the issue of using "impure" tap water as a base for the oil is raised. Is this a red herring as Ancient Minerals Bath Flakes are meant to be used with tap water baths and foot baths? (One poster has recommended letting the flakes "melt" and using this as oil).

In general, is there any cost effective way to source quality Magnesium oil? Tweet