Cost to replace rear engine seal. on 2008 Mercedes-Benz ML320 CDI

Was advised when had "B" service at 17,000 miles that it was leaking even thou had no oil spots on garage floor and only had to add 1/2 qt in one year. Doyle

Asked by for the 2008 Mercedes-Benz ML320 CDI
This is pretty costly. It will require to take down the transmission and other components. You are looking at long hours and depending on labor charges it may get as high as 2-3000 $