I have the feeling that your budget is too small for your building site and that is why you are not taken seriously. What does the square meter cost with you?

Yes, too little money and above all no plot of land. Many want to build these days, but most are building castles in the air and thus wasting time. Those without a plot of land fall into this category.

And do not fall under the misconception that new buildings are cheaper than used properties. It may be the case in exceptional cases, but as a rule, new construction is considerably more expensive.

No, unfortunately that won’t work like that. The 250k for the house is already ambitious and the €17,500 even more so, especially if that’s supposed to include all earthworks, soil removal, etc. How high is your real estate transfer tax? With your assessed land price of 100k, that alone would already be 6k for us.
Your calculation is basically tight everywhere, so as soon as one item goes over budget, no other can make up for it, because where is a buffer?

The real estate transfer tax is 5%. Correct me if I’m wrong. A house for 250k is doable (or these are lure offers whose purpose I don’t understand). But there are plenty with more budget and that’s more profitable for the companies.
Two examples:
The prices and construction service descriptions from Danwood are public. A house interesting for us is listed there at €170,000. I would add €20k for earthworks and €20k for the foundation slab. With a generous €30k for upgrades, we reach the €250,000. Or else less equipment if earthworks/foundation slab turn out more expensive.

At the local provider we received a price list offering a house of the suitable type for €215,000 including earthworks and foundation slab. The equipment there is already solid. Even if we calculate some additional effort for groundworks and upgrades, we are still within €250,000.

All work around terrace, carport, garden, etc. are naturally items that can wait if we initially need the money elsewhere. We also do not have the claim for upscale equipment. Photovoltaics, geothermal heat pump, etc. are all not must-haves. If in doubt, a gas condensing boiler is sufficient.

And don't fall under the misconception that new builds are cheaper than used properties. It might be the case in exceptional situations, but generally new builds are quite a bit more expensive.

For us, the impression was more decisive that in the used market only properties are available that need complete renovation. The costs are difficult to calculate, craftsmen are scarce, and we do not want to live on a construction site for years and renovate gradually. Sure, you could buy something like that for €320,000. But will the remaining €80,000 be enough for the renovation? You just don’t know.

And do not be under the misconception that new buildings are cheaper than used properties.

I would say new buildings are priced in the middle between used and consumed properties. You accompany a new building during its construction, whereas with a renovation project, you first practically have to trace it back to the shell, which is ultimately its value – with all the surprises lurking under the plaster. Therefore, in my opinion, as a new building alternative you should only look for renovation projects (i.e., painting and moving in, technical building equipment can remain) – meaning properties up to about 20 years old as a search filter. Older ones should be left to optimistic Rabotniks: only for them is it suitable and only in their eyes is it even more than just an alternative. You have to look deeply into your own eyes: if you were already a brave musketeer and jack-of-all-trades with all tools as a child, then it may (or must?) be a fixer-upper – whereas if you already look in the yellow pages at the slightest clogged sink, it's better to build new and you shouldn't expect much from used properties other than to learn to be afraid.