Current installation costs of a heat pump

No, you simply look for suitable offers on the relevant portals. For example, the following offer BEFORE subsidy or from Daikin BEFORE subsidy

interesting. Could you please provide sources? Thanks

Interesting. Could you please provide sources? Thanks

You can use all typical portals. The examples were from Kleinanzeigen, formerly Ebay.

It's funny that none of the 3 providers of these [mMn.] dubious offers, which I quickly looked at, are registered with the Chamber of Crafts.

Untrustworthy

Funny enough, none of the 3 providers offering these, in my opinion, untrustworthy offers that I quickly checked are registered with the Chamber of Crafts.

Untrustworthy? No.
Registered? Partly - if you need that, there are simply fewer providers.

You can also go to the big providers. Thermondo offers similar prices.

everyone has to decide for themselves anyway...

How do you obtain the funding if you do not receive a specialist contractor declaration?