Clear answer: Nope, doesn't work.
210,000 - 38,000 leaves 172,000 - 30,000 ancillary construction costs, leaves 142,000. Even with the cheapest prefab house companies, you only get a shell house for that. Even with your provider, it doesn't work....
Read up on some ancillary construction costs. They are around 35,000€ here without a basement on a flat plot. The land purchase also requires quite a bit of additional costs.