I have been investigating this and comparing prices between VRS and Overkill Engineering one.
Here is where it was brought up. No offense intended to the original poster, just point out what I have discovered.
Here I will be comparing 3" Aluminized with no muffler.
VRS:
~$345 Shipped
~$445 Shipped with Resonator
Overkill:
~$240 Shipped
~$300 Shipped with Resonator
Now Blair did bring up the VRS Piping Kit, that is a great way to go if you weld yourself or if you can get it welded cheap. Otherwise it's just pipes and flanges, etc. (Price is about $180 shipped).