Most of the pyrites consumed in the United Kingdom come from Spain; this Spanish pyrites generally (not always) contains enough copper (say 3 or 4%) to make its extraction from the residues ("cinders) a paying process, and this of course cheapens the price of the sulphur to the acid manufacturer.
2
This often cheapens a pen and the recipient takes little notice.
3
It's also so freely available it just cheapens it innit.
4
It cheapens astronomy, like using Beethoven for commercial jingles.
5
Telling someone it's over via text messaging cheapens the relationship and leaves a lot of questions unanswered.