Sure, lets say $500 for a heat pump, $50 for a heater. Then what 'yield' are you getting on the $450. Let's say heat pump is 2x as efficient (should be understimate). Let's say that you run 2kw normal heater for 1 hr / day winter only for 3 months. That's 180kwh. @12c that's $21.6. So you save $10 a year. A 2.2% yield tax fee. So admittedly not great.
OTOH a mining rig, well who knows that IS complicated. You might lose money, or spend a lot of time tweaking but break even.