For my region, that would be a decent solution, but I'm not able to build a shed for the rules where I live.

In wildfire prone areas, a burning shed might be even a larger liability not only to the residence but also hundreds or thousands of homes in the area.

These are very small sizes compared to a whole-house system or even one that could run my servers for 24 hours, but the NMC power bank could easily start a house on fire,

Can I ask if you've acquired a battery fire blanket or box that you could use in an emergency for your smaller packs?

and the LFP units could easily fill the room with highly toxic smoke.

This is my concern for my situation. Not only is the vapor produced highly toxic for inhalation, but also a very high concentration of hydrogen (35%-55%). I'd thought about trying to build in a ventilation system that I could engage, and then a follow-on detection system that could trigger the vent to run, but with that high a concentration of hydrogen, I'd be worried about the vent fan or relay igniting the hydrogen from a spark.

So today, I too and using the YOLO method. I've purchased really high quality UL 9540A Compliant LFPs, but that only goes so far.

Here is an Alibaba listing for a solar panel manufacturer in China.

For me it shows a quoted price per-watt in Euros of 10 cents or less, though in this things you only really find out the real price when you get a quote from them.

Of course the reference price is probably EXW (at the factory, no shipping or taxes). Also even if they are willing to sell you 1 or 2 panels, the shipping costs will end up be a very large fraction of the total price, though in my experience once you have a big enough order from China to fill at least a part container load sent by ship (or, even better, a full container) the shipping quickly becomes a small fraction of the total cost since shipping a container over from a place like Shenzhen to Europe or the Eastcoast US is surprisingly cheap considering just how much stuff fits in one (unless you're moving very heavy stuff, space is usually what dictates the cost).

I suppose that if you have a large enough project to be worth it, you can pay a shipping agent to do all the work (you can even find some on Alibaba) or even get the factory to at least arrange the shipping to your country (of course, for more $$$). Of course, the likes of DHL will hapilly pick it up from the factory and deliver it at your door, but by then the shipping costs are likely several times the cost of the panels themselves.

Anyways, all this to explain how big solar projects can actually get their panels at pretty close to those $0.12/watt because they have large enough amounts shipped by boat that the shippings costs per panel are very low, whilst somebody wanting to instally 10 panels on their roof won't get anywhere close to that.