Hopefully that was a dealer giving that estimate and not an indie mechanic.
The battery costs about $215 and an indie should charge about $100 to install it, including registering the battery to the car.
The battery is massive on this car and considering the number of issues that happen when voltage drops I would not attempt to install an aftermarket battery unless you can find one with similar specs. (I have yet to see one) A large Canadian Tire Eliminator battery will not be that much cheaper than an OEM battery purchased from a dealer like Tischer.
If you can find the AGM I would go for that option. It costs a little more ($215 vs $187) but it is a much higher quality battery despite it's slightly lower specs.
If you want more info just search here for AGM and you will find many threads on the subject.
Straight lines are for fast cars...turns are for fast drivers
'04 M3 - track
'06 650i Cab - daily driver
'02 Highlander - kid hauler
'01 330Ci - winter beater
Last edited by Yorgi; 01-09-2013 at 08:49 PM.