I'm doing mine for $433.28, not $800 to $1000. How? Glad you asked:
I bought the OEM oil pan replacement kit from eBay. Either search for part number 24117571227 or BMW transmission pan; there will be many models that have the 4.4 or 4.8 litre pan available, including gaskets, filter, etc. I chose to stick with OEM even though it cost more than the knockoffs. Cost? $185.12 shipped. Purchase 5 quarts Red Line Synthetic D4 ATF, $58.17. Take it to Aamco. The labor quoted locally is $189.99. They are cool if I supply the parts/fluid and they warranty their work but not the parts, obviously. Total? $433.28 including shipping.
'04 645Ci, Saphirschwarz Pearl/Black, auto, sport, cold-weather, 19" chromes, Logic 7, 7k white angels, MP3 retro, iPod retro, black grills/gills, Bluetooth retro, upgraded microphones, piano black interior trim
'12 Nissan LEAF, Cayenne Red
'10 Victory Cross Country, Black, too much to list
'01 Honda Magna, Black, too much to list