I have been running the top speed x-pipe for a year. Paid $475 shipped. It was too loud since it has no cats and no resonators so I added 4 resonators. They cost $200 plus $150 for welding. I did the cutting and tack welding and test fitting. I think top speed sells one now with two resonators but I wanted 4 for extra civilization.
I could have made an x-pipe or modified a stock pipe or bought a much more expensive brand name pipe, if I thought the expense and result would be worthwhile.