A while back, Chris @ SPD was selling the HKS axle-back systems for $205 + shipping. Ground from CA to DC (me) brought the final bill to $245 delivered. Now, you'd be lucky to get that system delivered for under $325.
One of the appealing things to the HKS was the price was far less than the 'cheapest' cat-back system. However, at $325 for the HKS it makes more sense to get the RB or Greedy full cat-back for another hundred. Especially if you look to go FI.