Is it an n63? If so a long block is listed at $4k from getbmwparts.com. I bought my m62 motor from them as they were the cheapest and easiest to work with for that purchase, by a long shot.
https://www.getbmwparts.com/oem-part...bC12OC1nYXM%3D
BMW lists their new motors as “short block”, but they are what we would consider a “long block in the US. Should have heads, water pump and oil pan installed. Mine even had the crank hub on it, but others I’ve spoken to who bought new motors didn’t get the hub. The Indy can rob the turbos, and good accessories from your old motor I would think.
See how that compares to the (itemized) price from the dealer. A bit more work on your part, but you can have it drop shipped to the shop. The unknowns can add up ( bad turbos, new accessories, lots of nuts and bolts, etc.) but they will add up as well, and for more more at the dealership.