Single post in Special birthday Cele visit!

Looking at the price of the Birthday Niet, it is 750zc. Assuming that's the price of all the birthday sprites, why should I pay 50-250 more zc for the ones I missed? Especially if it's only open on the DAY of my birthday and doesn't last a week? It seems kind of unfair that I have to pay more on my own birthday just to get a sprite I missed. I've been to a lot of places where if you tell them it's your birthday, you either get something free or you get a discount. I've never see a place charge extra.