These prices etc were from BMW
Motorworks quote
TRA95218 Bevel box output O-ring R1200 138mm X 2,62mm £4.10
K12/1300 Got one from bearing supplier for a few pence. BMW one is a non std size but went a few mm smaller and it was fine.
TRA79864 Bevel box output seal 80x100x9 (R1200 1 £15.76
K1200/1300)
AAA00081021 33117699630 gasket ring 1 £23.86
TRA20235 Bevel box ball bearing (R1200 1 £48.39
K1200/1300) I got a Std bearing from commercial bearing supplier £29.00 Ref Nos 6013 2RS-B-L195-R8-20 B0721 100mm x 65mm x 18mm
TRA74121 B/box output needle bearing sleeve 1 £24.66 R1200 & K12/13
TRA79862 Bevel box seal RH 60x75x8 1 £12.52
TRA65055 Cover for bevel box 1 £2.20
TRA10925 Final drive AX bearing 1 £54.41
AAA00081026 33117698132 bearing 1 £33.09
Link to OEM site
http://www.realoem.com/bmw/partgrp.do?model=0380&mospid=51731&hg=33&fg=05
I only replaced the large ball bearing, RH roller bearing and the large O ring when I did my drive recently. The large ball bearing is the only std one of the 2 that support the crownwheel shaft. The RH bearing is a non std bearing as are both seals. The large seal is non std, BMW being 9mm thick, with a std seal in the same OD and ID being 10mm thick. I can't say about the 2 pinion shaft bearings as I did not replace these. Mine is 09 which would be the same as yours.