I recently got an Omega watch, and wanted desperate to get the OEM rubber strap. The actual strap was $256 and the deployment buckle was an extra $256. So over $500 total. I got a great deal on the watch itself through a gray dealer and saved a ton on the watch itself so I pulled the trigger on the strap.
The buckle you can use on any strap on any omega watch which I guess is cool, but clearly super overpriced.
I needed to put back an extra link in a stainless steel band for a Baume & Mercier. I knew I hadn't thrown it out, but I couldn't find it. Replacement was over $70, so I lost weight. In the back of my mind I almost hope I don't find it. Why risk temptation.