Not trying to answer for James, but for comparison, From Yamaha the muffler and secondary pipe is like $220 and then the header pipe is another $150.
Hopefully James can get a sweeter deal because I am going to need one soon also. If its going to be in the $370 range, I will probably just do an Alba setup.
I done a header pipe mod and an exhaust tip on my OEM setup and LOVE it. Sounds great and I think I get a little performance out of it.