Re-roofing, roof tiles not possible

what is included there?

The offer from Prefa is still pending. This is an offer from "das Metalldach."

It includes: roof panels, curved ridge caps, verge profile, eaves sheets, sanitary ventilators, connection profiles, nails, BleiColor-SK red-brown, counter battens, roof battens, rough boarding, Delta-Maxx+ with adhesive tape, red-brown ridge roll, scaffolding, and disposal. And a few smaller items.

As mentioned, for 230 sqm area about 26,000 euros cost.

Why again can't the roof be reinforced for regular tiles?

Why again can't the roof be reinforced for normal tiles?

Because the current roof can only support 15kg/sqm. And adding extra load would likely be an extremely expensive matter.
And, according to my information, the ceiling beams are connected with the roof beams and form "a construction," so it would probably be very difficult to reinforce the whole thing.

I can only recommend asking some specialist companies. But in the description, do not specify the brand, only the max. load with 15kg/m2

I cannot imagine that they do not make cheaper offers.

At 15 kg/sqm, only a small amount of snow is allowed to lie on the roof.

I can only recommend asking some specialist companies. But do not specify the brand in the description, only the max. load with 15kg/m2

I can’t imagine that they won’t give cheaper offers.

There was already another roofer here once. He wanted 43,000 euros for the residential house (230sqm area), garden house (40sqm area) and garage (40sqm area). And we are not talking about an exclusive residential area (Munich, Hamburg etc.), but live in the countryside.

With 15 kg/sqm, there must only be little snow on the roof.

Snow, what was that again ;-) But yes, there is not really much snow here anymore anyway. So that fits, or rather, there is no other solution left.