House for 260,000 euros unrealistic?

Then I'd rather buy a condominium than be enslaved

Yes, servant of an owner, it is very tedious to discuss that, there are enough posts here that renting is cheaper, etc.. but currently the tight housing situation is simply nonsense and if you also have children or a pet, good luck.

What kind of house would I have had to build then, given the assumption of house costs in relation to land costs?

The available household income does not necessarily increase just because the land costs 25 times as much.

And in the small village, you can only put a doghouse on the 100€/m2 plot? Simply nonsensical logic.

And in Munich or Hamburg, a €4000/m2 plot must then have a €6 million house on it...

Then I’d rather buy a condominium than be enslaved

And under no circumstances will I ever buy a condominium. If I ever have to live in an apartment again, it will be rented. I believe that condominiums uniquely manage to combine the disadvantages of all existing types of housing. My brother-in-law, on the other hand, thinks that they mainly combine advantages. People are just different. And who enslaves whom? The big, bad loan? It doesn’t, if you adjust the house to the budget.

Opinions differ on that matter. I think a healthy ratio is important. In individual cases, however, it can also make sense to place a house worth 300,000 on a plot of land worth 1 million.

In our case, for example, the plot of land was only 1/5 of the house price. But that was just a coincidence, as the plot was a bargain and we were very lucky.