sorority joke dues

That's because some dues are all inclusive while others aren't. Some include all the shirts in the dues some don't. Some include certain events, others don't. The chart on there breaks it down a bit too.

Everyone knows sororities are expensive and a $100 or $200 difference is irrelevant. Lots of sororities also have payment plans, discounts if you pay all at once, scholarships, etc.

So here's a break down of dues per house since you seem to not have eyes to realize this.
ALL INCLUSIVE HOUSES:Meaning they include 11/11 events or 10/11 events
(Price Per Year)
AChiO-$1915
ADPi-$1774
AGD-$1843
APhi-$1818
DG-$1573
KKG-$1450
PiPhi-$1651

NOT ALL INCLUSIVE-Less then or equal to 9 out 11 things included in dues.
(Price Per Year)
ChiO-$1278
GPhi-$1600
DZ-$1796
Theta-$1443
SK-$2012

There's also a huge difference in price depending on how manh girls are in the chapter. The total fixed costs stay the same whether the chapter has 150 or 250. The "top" houses are much larger and therefore split the same expenses between more people.