Cost estimate for the shell construction of a 177 sqm bungalow

for free

For free? Excavation costs disposal. Topsoil is even hazardous waste and must be separated... just because a gravel pit or something similar is nearby, you can't avoid the costs.
I can't say much about the costs otherwise, but

Minimal earthworks

I don't see that here. What does the foundation recommendation of the report say?

The disposal of all excavated material, etc., I can do for free (company-owned dump, asphalt plant, etc.) but if I calculate with a price that I keep seeing 177sqm*500€ I would be at about 88000€ for the shell construction, and those are very realistic costs

then your planner should calculate the statics,
the soil report shows how deep you have to lay the foundation,
a strip foundation is required under load-bearing walls, I see several necessary here.
In our bungalow, fiber concrete was used and no rebar was inserted, the conversion for that came from the concrete plant

On the topic of fiber concrete, how big is your bungalow or more importantly: how many cm of fiber concrete did you apply, and with which fiber and at what price per m³? Best regards

I can dispose of all the excavated material etc. for free (company-owned dump asphalt plant etc.)
but if I calculate with a price I always read
177sqm*500€ I would be at about 88,000€ for the shell construction and those are very realistic costs

No, that is not realistic. I think you will be well over 100,000 euros. Depending on the federal state, where is the location? I would estimate about 110,000 euros.

Regarding fiber concrete, how large is your bungalow or more importantly: how many cm of fiber concrete did you apply, and with which fiber and at what price per m3? Regards

Our bungalow was calculated by the structural engineer, the strip foundations are 80cm deep, the floor slab 18cm thick,
the conversion from steel reinforcement to fibers (steel ?) was done at the concrete plant or by the general contractor?,
20 and 25kg fibers per m3, that was set at the concrete pump,
outside 155m2, living area 125m2,
we do not have individual prices