Maybe Sony hasn't listened. Maybe it's just how they're working out the pricing. This pack has technically less than the previous pack. Both tracks were available in Zone in the last pack. Only one is this time. Perhaps they just revalued to take into account that difference.

Maybe it's as basic as €1 per track run (2), €1 per Zone version and €1 per ship. I have no idea if that works or how it translates to the UK£ pricing.