Experience with on-rafter insulation from eBay?

Hello, has anyone ever had experience with NoName Aufsparrendämmung from Ebay or knows someone? Because the material (PUR alukaschiert 180mm) costs easily 15 euros less per m² there, which for 140m² amounts to well over 2000 euros.

2nd choice shouldn't be a problem, right?? Crooked edges, color defects, and a few dents don't bother me. In theory, I could even take 200mm for that and would still be significantly cheaper.

Hello Peter,
if the manufacturer of the PUR boards is a company from Bavaria that starts with "B" and ends with "L", I can tell you that it is a quality product. Possibly second choice, but the raw materials for the boards come from Germany. I am relatively sure about that.

Regards Fragi