[hotmilk400]

i would offer him $1500 for it since the O2 sensor is about $200, and the labor is whatever they want to charge. should only be 1 hour of labor (it would take them less, but they would charge for 1 hour) so figure like $300ish to fix the O2 sensor.

..

now if the O2 sensor wrecked the Catalytic converter or something dumb, then god knows what that could cost. your best bet is to buy a used one, which runs like $200 - $400 (and you can not buy them used at the yards, only from people you know who part out BMWS) not to many people had luck with new ones that are not OEM, and new OEM ones form BMW cost over $1k .

before you buy it, i would take it to get inspected and ask them if it needs to be fixed to pass inspection. some states, it does not even matter if the check engine light is on, and the sat or O2 is bad. i would not fix either if it did not need to be fixed to be able to drive it or pass inspection. some states will make you fix it (99% will only install new parts, so you will have to pay alot to get it fixed, or do it yourself. the car can run without the sensors, but the sensors are used to mix the correct amount of fuel before it goes into the motor. it also has to do with emissions, which is why it might fall inspection in some states (like mine, if it were a 96 or newer).

best of luck. take it to a shop and make sure it will pass .. if it does, i would offer $1500, and maybe pay the $1900 if you really liked it and it looked clean.