Yes. I am quite surprised. I thought the prices were disastrous here.
We all hope it's getting better. The HVAC trade union mafia has lobbied for decades to prevent the proliferation of environmentally friendly refrigerants, because only the high CO2 equivalent of the currently used F gases keeps them in business, because the legislator can't let "anyone" install these things. As a result, True Professionals^tm let the damaging gasses in the environment anyway, and consumer pays for this. (Although if the story about a simple $50 exam is true, then it's more like a mental barrier only in the U.S. It's lot more demanding here, the biggest problem is the required work time in a certified company.)
But this is all changing. Propane is really coming this time. Small appliances like fridges have already transitioned, and it is only matter of time all larger heatpumps will be, too. End result is, legislator can't forbid people from handling propane, and hence, cannot prevent self-installation of split type heatpumps, either.
Don't count on it. Back when it was legal to use R134a as an aerosol propellant it was a federal crime to vent it from a refrigeration system. When a gas is used as a refrigerant it is governed by different laws than when it is used for some other purpose. I have little doubt that it would be just as illegal for an unlicensed person to work with a hydrocarbon refrigerant, indeed it is currently a federal crime to charge a refrigeration system with propane, ostensibly due to the flammability danger. Propane is a very good replacement for R-22 though, its properties are almost identical, in fact the performance is slightly better, however it is highly flammable obviously. So yeah, it's pretty hard to stop people from doing illegal things, but the law can make it as difficult as possible for them to get the parts and tools necessary to do it.
For what it's worth, I've been running propane in the AC system of my 1984 Volvo for years and despite being totally wrong for the system which is designed for R12, it works very well. I suspect the fact that it's an old enough system to have a real TXV helps, the cheaper fixed orifice stuff is more fussy. The flammability makes some people go into a panic, however I reasoned that there is already some 14 gallons of gasoline on board which is circulating under high pressure so what more risk is 6 ounces of propane going to cause?