The costs are individual, you can only calculate that yourself. Is self-performance possible? What is offered to me, etc.
For us, with little self-performance, the air-water heat pump was already cheaper than a gas heating system. No gas connection, no chimney. A heat pump is not a miracle device and can be done for under 10,000€, an air-water heat pump can be significantly cheaper.
The operating costs for gas would be about twice as high for us as now with the heat pump
- Heat pump 360€ for electricity per year, no maintenance or other costs. Costs can be slightly reduced again through photovoltaics
- For gas it would be about: 460€ for gas + basic gas fee + chimney sweep + maintenance
If I had had to buy the heat pump from the heating installer for 20,000€, then the calculation would look different.
I also think that a heat pump does not last quite as long as a gas boiler, but that is just my unsubstantiated opinion. But even if our heat pump broke down every few years, nothing would change in the calculation for us.
Gas has the advantage that it does not require precise planning and as a builder you don’t have to deal much with heating planning.
If you plan properly and are not at the mercy of an expensive heating installer/general contractor, then I find heat pump + photovoltaics the most sensible type of heating currently in new buildings – economically and ecologically.