Any butane from Europe will cost more than butane from Korea or China.
How much something is filtered is usually what says how much it will cost. But we have talked with butane manufacturers overseas and they will put whatever filtration the buyer wants. So we do not believe that there is much of a difference in butane quality.
The smell in butane is NOT butane, but rather an additive called Ethanethiol
We do feel however that European and American butane is cleaner than any other.