$178 from BMW of Des Moines... Yeah its fairly expensive. ITs really not a big deal to have it fail full and just check the dip stick? I tend to go the other way and go cheaper on older cars. Like my X5 4.8i had its rear power hatch struts fail, so I put in the old fashioned manual ones for $45. Same with the sunroof venting, I just disabled the second one from venting so it would close reliably.

https://www.bmwoemautoparts.com/oem-...AaAjlwEALw_wcB