Prefab house made of Neopor - experiences?

As already said: Get offers and compare. How much is your house allowed to cost without land, notary, etc?

130,000 EUR

If this is the entire budget for the house, then forget it.

I found a post that fits your requirements quite well and read the numbers to you:
https://www.hausbau-forum.de/threads/250000eur-baukosten-brutto-fuer-efh-im-suedlichen-bw.28732/

Can confirm that. Please do not try to build a house with the budget. That only leads to tears. With double the budget for the very small house size (without a basement) and an extremely high amount of personal contribution, there is a chance of realization.

Oh, thank you! So once again to conclude: Even with Neopor stones, it ultimately doesn’t come cheaper? Many greetings

No, because the walls are not what drives the costs up.