If you try and sell something at the cost of production you will go broke very quickly. When you go to ACE hardware, open a drawer drop a nut bolt and a washer in the bag, go up to the counter PAY IN CASH $1.50 or something, they just hit you with a 3000% markup. . . and lost money on the deal, no question. Add in a swipe fee, and they are pretty close to paying you to take it.
In another life I ran a pizza joint, we kept our total CGS under 30%. I think it's a little higher in the business these days. Bigger ticket items can be sold with narrower margins, but I can tell you MSRP's represent a 60% Margin on most appliances or a 150% markup. Then they discount 25% example: 4 (cost) * 1.5 = 6 + 4 = 10 * .25 = $7.50, which still maintains a 1 - (4/7.5) = 47% margin, or just under 100% markup. Business' run on margins. If you don't have a storefront you can lower your overhead, but everything you do costs money. When I order 100 units at $1000ea and drop them in a warehouse I now put up $100,000, for a product I haven't sold yet. I paid for the freight as well. I'm paying rent on the building, the power bill, the water bill, and the paychecks for the forklift guy, and the clerks doing the paperwork, and ...
I guessing EG4 is running a pretty tight margin, 40-50%, I figure they are shelling out $2500-$3000 for the units. They are likely buying them by the container or 1/2 container or whatever to save some of the shipping, they probably have $3500 in it when it hits the US dock. Then we have any tariff's etc. There is just all this little stuff that keeps adding up. The 2 units that fell from on high and the couple that were speared by the forklift guy.
Sol-Ark had a corner in the 240/50A space of the AIO market, but as we see more competition in prices should drop a bit. For one thing manufacturing costs tend to drop, efficiencies improve, etc, etc.