It's not your fault, you don't know better. He is the only one to complain about the brakes, no one else had issues including myself with brakes that are bigger than those on the e46 M3.
BTW, the GT3 actual weight versus the 335i is less than 200 lbs difference, maybe even under 100 lbs. Edmunds weighed their test GT3 at 3283 lbs, C&D weighed their 335i test car at 3366 lbs. But you can go argue with the man about his track results, you have a log-in.
Those prices are way too high, that's what he gets for buying Dinan.
Decently equipped 335i e90 Step incl trip for ED: $42K
KW V3 $2K
BBS Forged Wheels $3K
Vishnu tune $1.6K
Quiafe Diff:$2K <--optional except for Auto-X, price could be higher if you get the welded differential
BBK = $3.5K <--optional but nice, also note M3 reviews complained about brakes so what's good for the goose...
=
$54K for a car with more HP, way more TQ, much better brakes, equal suspension, virtually same interior, much better fuel economy, 250 lbs lighter, better resale value, and all-around faster than an equivalent 63K+? (with M-DCT) e90 M3. Oh, and a free trip to Germany
and Q-ship cool points to boot!
Oh forgot 1 more thing in the prices above:
Look on drivers face in M3 when he has to give a wave around? Priceless!