It is, but it’s the only way to get viable heating without fossil fuels in a climate with winters. I have a friend with a ground source heat pump and one with an air to water heatpump and the former has a bigger house and significantly smaller electric bill when the real cold hits (January, February). Think it was 100-150 EUR vs 400-500 EUR + also needed to keep burning firewood every day when it got proper cold. Both use floor heating.

All in, you can count on it costing about 15-40k depending on everything. Air to water heat pump is more like 10-15k all in, but when you’re burning 10 kilowatts on resistive heating and your place is still not as warm as you’d like, you’ll know exactly why.