how expensive is being in a sorority here?

Panhellenic has all that information available. Ask them or your rho gamma. Each sorority is different so there's not any single answer.

This is what caused me to drop my chapter, dues can range from $400-$1500 for active members. And new member dues are usually more expensive

There's a link to the lookbook for primary recruitment on the Syracuse panel insta - it has a chapter and the dues.

A thing to know is that sororities might break out their costs differently from one another. Panhel can help clarify if you have specific questions once you get the info on all houses. What might look like a huge cost difference might not actually be that much--it just appears that way based on how own or the other laid out their dues and stuff. Overall, it's more expensive to live in a house than in the dorms. Every chapter has local or national scholarships and payment plans. It's important to be sure you are crystal clear on cost obligations. The worst is to accept a bid and then have to drop out.