This pipe was made in a small batch by Chris from MotoGPwerks. The cost was $400+shipping. He did make the cb750 pipes for carpy, and is a very talented dude. He worked for yoshi in the R&D department back in the day.
A few forum members got together and asked Chris to make a special set of pipes for 550s like he made for the 750s. He made them as a favor to the guys here, no profit involved, and it has been a big headache for him for a number of reasons. I don't expect he is going to make any more, and I don't blame him at all.