I'm reminded of fluorine chemistry. Back in the days before the Montreal Protocol you could get all sorts of halofluorocarbon starting materials for pennies bec

I'm reminded of fluorine chemistry. Back in the days before the Montreal Protocol you could get all sorts of halofluorocarbon starting materials for pennies because they were byproducts of CFC manufacture. But nowadays cost is prohibitive, a 100 g can of CF2Br2 will set you back hundreds because it's a specialty chemical and the paperwork is outrageous. It's a genuinely small sacrifice for most, but for a select few there's great cost.