If you want to look at a place that is comparable to (parts of) the US that manages to do things about 3-4x cheaper, look at Australia. They seem to have stumbled on something that works ridiculously well. You can get a quote and stuff installed in something like a few weeks at most. It's done right and efficiently without a lot of bullshit.

Other places (like the EU and especially the US) have regulatory problems around anything to do with energy. This is mostly about ass coverage resulting in a lot of pressure for certification, related fees, grid operators insisting on a lot of overhead, building codes requiring a lot of faffing about for the business of wiring together what is essentially plug and play stuff, etc.

If you have an off grid shed, providing power to it is cheap and easy because you have none of that. You buy the hardware on amazon or wherever. It arrives, you wire it up. Job done. And if you are smart you might let a qualified electrician do it right for you or at least check your work (so your shed doesn't burn down and nobody dies from electrical shocks). But fundamentally it's not that hard and this stuff is mostly pretty safe and easy to work with. Especially compared to the things people burn down their sheds with traditionally (e.g. generators).

There's a lot of optimization potential here and most of that is completely non technical.