The bigger they get the more they cost.
And the fewer choices exist to choose from. That alone tends to drive up prices.
Used a water-cooled 5kW load years back. Had a blown resistor when I got it. But the Ebay price was stupidly low. Probably because the resistor was blown. The replacement (in 2003) resistor cost 160 bucks, but the bottom line still looked good, including the price of the water pump, hoses, radiator and fan. Worked great until one day the water pump stopped. Sure enough the resistor was toasted.
Been using a Bird oil-cooled ever since.
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