I just ordered my parts thru the BMWPartsstore.com which seems to be cheaper than Tischer. I would also recommend replacing both the fill and drain bolts as they have washers that should be replaced anytime you change the oil.
Here is my shopping list for this transmission fluid change
Transmission filter (# 24-11-7-593-565) $43.32
Gasket (# 24-11-7-572-618) $39.02
Oil Drain bolt(24-11-7-572-622) $1.51
Oil Fill bolt (24147572603) $13.38
Redline D6 fluid (from Amazon) - $11.49 x 7 quarts
E92 Xdrive / Montego Blue / M3 Black Novillo Leather / OEM 351M 19" Wheels / Mtech Rear w/ IS Diffuser / Aero Lip / LCI Tailights / M3 Steering Wheel w/Paddles / 40% Huper Optik / Lux V3 / 4300K HID Fogs / Dynavin N6 / 3 Stage Intake Manifold / Magnaflow Dual Exhaust Conversion 4" Tips / K&N Filter w/ charcoal delete / Active Autowerke Stage 2 Tune / KW V1 Coilovers / BMW Performance Strut Bar