Too many people underestimate the value and importance of parts warranty.
Some people nowadays are importing parts from overseas themselves. The problem is that you don’t know what the quality is like.
Countless companies who sell on web sites like eBay claim they sell original equipment manufactured (OEM) parts, only to find out that the quality is not OEM. Proper OEM parts are from manufacturers who actually supply for BMW directly, so the quality should be equal to the original. The parts from many of these internet companies are not OEM and the quality is appalling and in some cases unsafe.
Many people who have also purchased parts from overseas know too well the difficulty when claiming warranty. Not only is it difficult to get warranty but they have to pay the freight charges again, not to mention the labour again to have it replaced a second time. BM Tech highly recommends against this due to the far-too-common poor outcome for customers.