I cannot comment on the battery.

As for the brakes, is that quote for just the fronts or for all 4 corners? If you want OEM parts. getbmwparts.com has the parts listed as:

Front Pads: $149.63 (both wheels)
Rear Pads: $127.93 (both wheels)
Front Rotors: $129.92 each
Rear Rotors: $141.47 each

Or you can go to BMPdesign.com, Bavauto.com, zeckhausen.com to purchase brakes and brake kits. You will be able to choose between OEM or aftermarket depending on what your budget may be.

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2012 X5 50i ZAP(2VA, 336, 465), ZTP, ZPP, ZPS(6VC), ZCW, ZRC, 322, 4UB, 4NC, 610
2011 ///M3 Silverstone II
2011 X5 50i(lemon)
-- SOLD --
08 550 Msport
07 X5 4.8I sport
04 545i sport
02 4.4i sport
01 540I M/sport
00 SL500
97 SL500