Partially I suspect the increased Dutch gas heating prices have caused the price of "warmtepompen" (electrical hot air machines that pull in outside air) to increase dramatically. As businesses faced with massive gas bills rush to buy every available one.

Buying and installing a warmtepomp at 3 times or more the market price might return that investment in 5 years, but gas prices are already going down, so that might not be worth it (even though you should invest in one anyway for environmental reasons). Buying a mining rig that has sharply dropped in value recently and changing how the fans on it work, is probably cheaper than buying one of the hot air units right now.