Laying main pipelines

It also depends on how deep the digging is.

Approximately 1.00m

I wanted to roughly calculate this:

In total, I need about 66m of KG main line with DB 125. The cost per meter is approximately, say, €4.50.
That amounts to roughly €300. Plus seals, branches, and bends, let's estimate it up to €350.

I can't do much with that answer.

Why can't you do anything with it?
You can't calculate €4.50 per running meter when the earthworker MUST include his equipment in the running meter besides his working time.
If you have such equipment yourself, then you can very well only calculate the purchase price, but in craftsmen's calculations, their machines and equipment are always embedded.

And as already described above, €900 is very little.

Concrete example: our running meter installation KG 100 cost €34.50, plus the connection work and pressure test of €200 each.

And if a self-employed person charges €55 labor wage, then at most half of that remains after all costs have been deducted.
But by now, everyone should be aware of that.

I think you didn't quite understand me..

I'm not charging €4.40 per meter for "ready KG pipes installed and accepted"!

I only assumed the material cost as €4.50 in order to then estimate whether the remainder left over is plausible or not...

No, you don’t understand!

1. A calculation is handled differently than you present it in #1 (and question it)
2. You can calculate it yourself, because according to your calculation, a squeezed 8 € per running meter results.
That someone might still ask whether that is a bit too harsh or too much is already embarrassing.
I assume there is an error, missing items, or someone who pursues a digging hobby.

No no, you don’t understand anything but by now it’s pointless to try again when it didn’t work after two attempts

But I thank RFR and Emer for the constructive contributions

Regards