@SupaPhly part of the reason could be that they are more responsive to FOREX fluctuations than MS or Valve. The other reason is that we are so small for Sony that they can't be bothered to match what happens on the other platforms.
If you have both consoles it allows you to price shop, i've picked up a few games this way.
From Quantum Mechanix. Our Firefly Pretty Cunning Lapel Pin let you channel roguish mercenary Jayne Cobb without messing up your hairstyle. Enameled in yellow, orange, red and black, its fine details show off Ma Cobb's handiwork and lets the Verse know you are pretty darned cunning. Jayne will be growling with pride over this favorite piece of headgear, and we suspect, so will you.