I think I paid $430 for my pacesetter longtubes back in 06 and I got 25RWHP and 30RWTQ just from the headers and this was b4 the supercharger went on.

 

I would say the price is about right.. long tube headers will help with scavaging also.

as for if there worth it. in most cases the benifits are . slight increase in hp and torque, and 1-2 mpg and exhaust sometimes will get slightly quieter