Single-family house - What can a trapezoidal sheet metal roof - folded cost?

The roof only has a 10-15 degree pitch, as far as I understand, tiles are not an option there.

Where did I overlook that? - yes, under 20° roof pitch, many roof tile manufacturers are out.

Currently there is a corrugated roof and a metal roof is then generally suitable.

Corrugated or standing seam is definitely a difference.

(Where) did I overlook that? - yes, under 20° pitch many Dachstein manufacturers are out.

No, not overlooked. I just initially considered it irrelevant. But since you said we want a "fancy sheet metal roof for free" I wanted to say that "fancy" was not the primary motivation here. Yes, I found standing seam already nicer, but a low trapezoidal roof also didn't look bad.

Our Creaton Sinfonie roof tiles (engobiert) can also be installed with special sealing <15 Grad DN, according to the datasheet... Really like them on our roof. Quite large and heavy, but worth the price!

Our Creaton Sinfonie roofing tiles (engobed) can also be installed with special sealing <15 degrees pitch, according to the datasheet... Really like it on our roof. Quite large and heavy, but worth the price!

That is not possible from a structural standpoint, which is designed for something light

Trapezoidal sheet metal is unbeatable in price. Mine cost 12 euros per m2. For lengths up to 9 m, it can also cost 20 euros. I installed it myself then. Only the screws are added on top.