I've been told these cars need valve jobs around 150k and it would run about $3k. Is that correct? Why is it that much? Do you need to replace the valves?

My car had the valves done when I bought it, I have the bill and it was around 3K. Yep, all new valves. The good news is that the bottom ends of these motors are bullet proof. The S38 is known as an overbuilt engine, as evidenced by the number of high mileage M5's on the road. On the contrary the current M3 motor is underbuilt. There won't be too many original 150+K mileage E46 M3's out there in 10 years.

$3k sounds about right.The tech usually sends it out to a machine shop so there is one mark-up.Then there is the labor.I had my head rebuit on my 535i last year when I thought I was going to turbo it.

So you NEED to replace the valves?

not necessarily, but new exhaust valves are usually a good idea if you are already that far in there....