What’s up with R134 prices?

AbodyBB said
Also r1234yc operates at much higher condenser pressures so it requires different compressor and higher rated system. And Mercedes Benz still refuses to us it because in the first test they witnessed, it caught fire in standard accident conditions

Where are you getting that r1234yf (idk where you're getting the c from ether) operates at a "much higher pressure"? It is true that r1234yf is more flammable than r134a.