If its a Greddy Sp2 it will say Greddy right on it, just check it. My Sp2 has it right on the exhaust. Here are some pictures of my Sp2...see on the tip.
Exhaust is Done
How used is it? Is it rusty? $350 for a really used exhaust that may have some rusting or some damage to it...seems like a lot to me. I bought mine brand new for like 4 something I think...cant remember.
I have more pictures if you want them...they are from the underside of my car with the exhaust on.