It's interesting to see the diversity in dues.
When I joined my local, dues were $100 for your pledge semester and $50/semester thereafter. The pledge semester dues included your pledge ring, badge, and sister shirt (matching lettered shirts in the sorority colors that were presented to the pledge class after initiation). I wasn't complaining about the low dues
but the sorority had very little money in the bank.
When we went AEPhi, our dues for our new member semester became something like $450, and maybe $250/semester thereafter. We didn't have summer dues (no one did). That's still the least expensive on campus, mainly because the other four NPC sororities either had houses or were actively seeking housing and raised their dues in order to have money for a down payment.
ETA: During formal recruitment, we gave out little half-sheets of paper with the breakdown of dues for the new member semester and for a "regular" semester. This was the only thing PNMs could take with them. So PNMs knew right up front what they were in for.
Someone mentioned asking about finances during recruitment. A word of caution: At some schools, where rush is very competitive, asking about dues could get you cut (the "if you have to ask, you can't afford it" mentality). It would be safest to ask your rho chi if it's ok to ask about dues; if it's not, the rho chi may be able to provide high/low/average dues amounts, so you know what you're in for and don't get sticker shock and depledge when you get your first bill.