Yeah, but unless you can install it yourself you're gonna have a shitty experience. 5/6 companies I called up wouldn't even touch my self bought equipment, and the one that did charged me out the ass for it. Basically, something like 10k-15k in labor costs. It's bullshit. And for anything warranty related you need the license number of the installation contractor before you can even file anything.
Installing it didn’t seem too bad… You can get ones with pre-pressurized lines and you just cut a hole through the wall and put it on a cement pad. Saying that, I might be a bit more comfortable with hands-on things than the average person
Depends on the system, the living space, and the existing HVAC. The box itself can be well under $2k USD, but things like upgrading your ducting can add a lot to the bill if you have a central air system.
Heat pumps installations are a racket out in the US right now, it's artificial expense to pad out pockets, there is no practical reason it need be that expensive.
Might be a regional thing. Here in Australia our houses often have sliding windows, so it's not hard to open one and mount an aircon in the space, sealing around thy edges.
I think some other countries use hinged windows which are less amenable to being violated by a Window Rattler. Placing the entire unit inside against the window and creating some improvised ducting for the outdoor air inlet side can also work in a pinch.