Do some of you really believe that BMW is so stupid that they'd make the M3 model only marginally better than the 335. These are two different cars, this is old stop comparing them.
If you think the 335 is so much better and offers a better value (chips etc) then buy one and stop winning about how the cheaper BMW is so much better than the M3. If you think the M3 is a rip-off than go buy something else.
No matter how much you mod an 335, it will never be an M3. You can spend 20k to make the 335 faster than the M3- this is true. However, just because you tune a Nissan 350Z to be faster than an F430 doesn't mean that is better car. They are each unique. Get what best fits your needs.
Everyone who thinks the 335 +proceed is an M3 rival is a total idiot