K.B.
I live in Oak Park and love resale too. There are two Once Upon a Child stores kind of accessible: Villa Park (Roosevelt Road) and Harlem/Foster. The second one just moved to this new location from Central/Foster and I haven't been to the new space, but in the old space they had a tremendous selection.
Keep an eye out too for the Parenthesis consignment sale this spring (March?) -- they collect stuff locally and sell very reasonably.
In the back of Chicago Parent there are resale shops listed, check those out as well.