Odoo V12 Debian/Ubuntu Self-Hosted

Hi I created a product (with BOM) one of it Parts has a scaled price. up 1 pc cost 2,5€ at 20 pcs cost 2,10€ for example.

the Question is how can i take the scaled price to the BOM so that my product has the correct price i.e.

now it calculates like this BOM001 Article hast part 1 (0,50 €) part 2 (0,50 €) Part 3 (0 €, because it doesnt reads the scaled price) cost of the product 1 €

How it should be BOM001 Artikel Part 1 (0,50 €) part 2 (0,50 €) part 3 (2,50 €) cost of the product 1 Pc = 3,50 €

BOM001 Part 1 0,50 € Part 2 0,50 € part 3 2,10 € cost of the product if i produce 21 pcs 3,10 €

Any Idea?