2004 X3 2.5L Im told I need a DME? Codes28B2,29B5,27A1,2796

My X3 is turning over only to stall. It seems like cold weather might play a part. It will do this over and over and then will go into a "safe mode? rough idle where pressing the gas pedal doesn't work and the car idles at 10,000rpms. If I disconnect the battery and keep re starting it, it may go back into a regular run condition where there are no problems. This will last the wole day until the next frigid morning, when it won't stay running again...
I took it to a shop that advertises a BMW certified mechanic and got Drivability codes above. They say I need a new DME(Computer) at $1500. with only an hours labor. Does anyone know? I am scheduled to go to the local dealer for his diagnostics, because the Service manager there said that he has never had to replace a DME, that it's probably something else.

Did you resolve this problem? I am having same issue with my 2005 X3 3.0i and am told I need a new DME.

whoa whoa whoa, before you start dropping $1500, have you had a second opinion anywhere else? Is your DME 413 red label? I've seen a few floating around for like $100...

Thanks for replying, jdauria.

I haven't had a look at the part myself yet, just took it to an indie mechanic for inspection. He read the codes, found me a "service bulletin" published by BWM - 12-49-06, and asked me to go to the dealership for replacing the DME. He also said, they might give some discount on the part because of the bulletin.
I am not very fond of driving to my local dealership having read the countless bad reviews online.

Do you think I should buy the part online and replace it myself? I heard there is some programming involved which only BMW Dealerships can do, is that true?