"New" engine won't solve the problem because you still sink money into the valve stem seals!
1. Best option is dealer tech working from home. This fellow is from Long Island NY and charges $2500 for it:
Valve stem seals done for $2500! - Bimmerfest - BMW Forums
2. If you DIY, then it is mostly parts, labor is yours:
http://www.xoutpost.com/bmw-sav-foru...-pointers.html