New/rebuild?

[Ssolidarity]

Is there any way to buy engines from BMW, or would it be cheaper to rebuild my current power plant?

[Aleksey]

? Junk yard.

[jlevie]

You can get a new engine from BMW, have one rebuilt, or find a good used engine at a salvage yard. What to do depends on what your expectations are and how much you are willing to spend. Cost could range from as high as $8k to as low as few hundred dollars.