Don’t Convert to R134a

If memory serves, Dupont owned R12. They knew the patent was running out after which time others could make and sell R12. They developed R134 as a replacement with a new window where they are the only supplier, then provided all the R12 data they had been sitting on to the gov (who don't know better than the mfg and just react) so nobody else would get to make and sell R12. It's a cycle.

When banned the price of r12 peaked as most everyone was converting to r134, then the remaining supply had few buyers so the price came back down. Timing is everything.