Our best offer (out of now 5) for a photovoltaic system is €13,000 for 7 kWp.
Have you deducted tax? Without tax, such a small system shouldn’t cost more than €1,500 per kWp. From 12 to 15 kWp, they are currently aiming at €1,300. (And those are realistic prices – I saw the last offer with that price the day before yesterday. In expensive BaWü.)
The first step now would be to look for space for more kWp. 7 is really quite small. Many solar owners don’t even get out under 10 anymore. All roofs are suitable, often even north-facing ones.
The second step is then to keep looking and possibly wait. The market is really overheated right now.
Or a significantly larger self-consumption through e-cars or something.
E-car and heat pump both come within the system’s lifespan. Therefore, you can certainly credit a bit on the positive side in your calculations. And until then, don’t be upset but enjoy the really excellent low house consumption. Saving is actually even better than self-consuming! ;-)