You can't legally break into the business, but DIY on your own house is entirely possible: the equipment is available for 1/4 to 1/3 of the "installed" price and some of the more climate-friendly refrigerants do not require an EPA license to purchase.
Yes, the work involves electrical, light plumbing and welding, a specialized tool or two, attention to detail, and definitely physical labor, but for a lot of engineers that's just fun stuff to do on a weekend - really fun stuff when you save over $10K per installed system (at the 3-5 ton unit capacity level.)
Certainly it’s not for everyone or even every engineer but I guess my point was that if you’ve already done most of these things yourself it’s not a huge leap to DIY your own HVAC install compared to the financial incentive, especially if your house has more than one system.
Beware that the article is not very clear and talks about "heat pumps" as a general concept when the term actually encompasses a bunch of different and very differently priced things. What Øyvind gets for $2,630 including installation is a wall-mounted air-to-air heat pump like this one:
https://www.polarpumpen.se/varmepumpar/luftvarmepump/mitsubi...
Something like this will be great for heating a single large room, a small house with an open floor plan, or a secondary space like a garage, but is not a system that will handle an entire normal-sized house. But yes, you can get it for $2,630 including installation and it is very efficient at what it does.
Most of the heatpumps available are about 1200USD cheaper, but only go down to -25C, which really is plenty where most people live (not too far from the coast). Installation typically costs around 600-900USD it seems.
Given our 25% sales tax and high wages it should be considerably cheaper in the US.
That's probably not the only reason for the difference, but it is probably one reason.
Only new and emerging tech on the market are subsidized. When adoption increases they remove it as the goal is to decrease cost of newer and less common methods.