POE2 Sale Mismatch?

I wanted to buy the nightfall armour pack as it is 25% off at 315 (instead of 420)

However when you click the pack the maths doesn't add up as the total cost of the pack is not in fact 315 but 540!

What is going on, why is the price advertised at 315 when it costs 540? I can't find a way to buy the whole pack at that price.