Just look at the cost of the upgraded intercoolers for the N63 motor. I was thinking of adding them to my tuned X5 50i Dinan but altogether about $3000 with labor for a gain of around 15-20hp. I already have the software and Dinan exhaust and this thing is a beast. I have not decided what tune for my F13 M6 but am waiting to see what Dinan has coming up. They have a program for the X5/X6M S63 engines so I am assuming they will for the S63tu. Only time will tell. And yes they will be expensive. I had all the Dinan mods for my E64 M6 and other than the stroker motor, the parts and labor were in the $15000 range for a gain of 60hp.