I sent an email to Kelleners asking about some prices...
We can offer you the following parts for installation in the US
camshafts
ECU upgrade
sport cat
airfilters
exhaust
all the above are for a proper BMW mechanic easy to install.still you have to make sure they are able to do more than yust go by the rule book.
changing the cams and ECU will give you the most torque and power (35 nm/35hp)
price 9.000,-DM
the next step is to add the catalizer.it will give you approx.15 nm and 10 hp.
to install this part the mechanic needs to be flexible.it will come with all the correct connections but to fit it the connections have to be welded on.
price 2.700,-DM
the exhaust will provide the best possible sound and good optics.(2 to 4 hp)
price 2790,-DM
airfilters 280,-DM (2hp)
to modify the ECU we either need it to be here for a day or somebody with a laptop
and software skills could play the data on online.
Just thought I would share it with you guys. I am sure this info has been posted before somewhere, I just could not find it.