Exhaust Question, Opinions needed

2011 Nismo#91

1) Price does seem fair, you might find cheaper in the private classified but shipping is a killer.
2) Not much of a difference, it flows a little better the stock but not by much and it's pretty quiet too hence why people sell if for so little.
3) Sound shouldn't change much. Though I never heard that setup in person.
4) Probably not, depends on the condition, if it looks like almost new and no rust on the muffler can then maybe.