How much house/loan can I afford?

Building is certainly almost twice as expensive.

I don’t believe that, though. Not with the expectations of the OP and a village in Saxony-Anhalt. You can still build for less there than in large parts of the country.

If the price for the plot works out like that and you subtract the incidental building costs (which will probably also be below the always mentioned 35-40k €), in the end you would probably have around 140-150k € left to build. That would certainly be tight for house + prefabricated garage. Whether it would be possible??? – I’m not sure.

The big unknown, however, is certainly, as already mentioned, the partner who may hopefully come in the future. A small house in the village is certainly not everyone’s thing. Where would the journey go then? Sell everything again? – That would certainly not be easy in that area either, and the resale value wouldn’t be great.

I agree with you. Despite everything, it is always a question of what one wants/can imagine. If the OP "only" wants 100 sqm without a basement, with a small prefabricated garage without the, as you so nicely said, "frills," then that is also okay. And I myself wrote that I am not sure if the budget is sufficient. It should be clear that there is certainly no financial leeway for any additional wishes. Accordingly, the advice to also look for existing properties is certainly correct. Whether one wants that and what the market offers is another question.

Yes, I agree with you.