I think what the OP is saying is that the national sororities on her campus have a high financial commitment that is, essentially, a barrier to entry to some potential members. All she is saying is that she wants the sisterhood that a sorority offers but without that financial barrier to entry.
But you can definitely have those strong bonds of sisterhood at a lower cost. Just be aware that some of the things you can't afford (e.g., a chapter house) are things that build the most lasting and meaningful memories among the sisterhood. You'll just have to find another way to build those memories! It will be tricky and if you deliberately do without the fringe benefits that come from having a higher operating budget, you'll have to fight the perception on your campus that you are not a "real" sorority.
Best of luck.
