Danwood Family - Project realistic?

Hello to the forum. I am new here, an absolute construction layman, and hope for your help. We (45 and 41) are currently considering whether we should still undertake a house building project or not. We could get a good building plot relatively cheaply, but the budget would probably be quite limited at 450k, according to my previous research, although it's not calculated down to the last penny, but we actually don't want to spend more money. The requirements are low, a simple Danwood Family house with 110 m2 and a list price of 245k should be the basis. I have been researching for weeks now, but now I simply need help from people who have experience in this regard. Accordingly, I have put together a very rough cost plan and would like to know how you assess it, whether it is even remotely realistic, or if we should better leave it alone. The building site is in the deepest part of Baden-Württemberg.

Who created the list? Is it really the case that you have to pay extra for every little thing at Danwood Family? I only know about E-cabinet, BoPla, architect, and transport in addition to the usual extra costs. Take a look here in the forum under the Danwood houses. The house connection is a bargain here. I don't think the city would install your electricity and water so cheaply.

I created the list to the best of my knowledge and belief but as I said, an absolute construction and craft layman, these are my research results. However, the figures for the house connection are indeed actual values from the neighbor.

So the surveyors around me (also in BW) unanimously demanded a flat rate of 2600€. The interior and exterior plaster should really be the entire plaster, or is some of it already included? My offers are around 18000€ (however, the house is bigger (152 sqm) and includes a basement, where only the interior walls and joints are puttied/plastered) for lime plaster, the second layer for Q3 again 12000€ for lime plaster as felt plaster. Exterior plaster 24000€ + mesh putty 5000€ + mineral top plaster 4500€ + leveling coat 4000€. Technical room with meter place is about 6500€ for me, yours could fit there. Painter including textured wallpaper on the ceiling including basement is quoted at 15000€ for me. Floor coverings themselves are 40€/sqm tiles and another 50€/sqm for laying including adhesive etc. Photovoltaic system would only allow the absolute (mandatory) minimum if the kitchen also has to be paid for with it. What you mean by flat roof I unfortunately do not know. For me, about ~10% (exact number unknown) for construction management should still be "hidden". He doesn’t do it for free.

There is probably a missing 0 in the connection costs. Never ever do the providers lay the lines on the property for a few hundred.

The basic data all come from the neighbor who built with a different manufacturer. It is of course possible that there is actually a missing zero at the house connection. However, my main concern is to determine, taking into account your experience, whether the budget is basically sufficient or if I am misinterpreting or forgetting something important.