Hubblyking.
I showed my workshop manager this thread, as well as googled images of a standard E46 M3 exhaust fitment, and an X-Pipe fitment.
There are unfortunately a vast variety of different x-pipe fitments, that it is difficult to quote "off-hand", it would be dependent on which type of fitment you want.
My manager and exhaust technician said it would be better if you pop in for a "coffee" to then discuss your needs and then we can see the work requirement and quote you accordingly....maybe you can give me a link to an image/images of the type of fitment you are looking to get.
on the Tailpipes, cost is dependant on which type we use, but the cost is about R450 for single to R600 for the dual tailpipes.