I generally rent from Budget at O'Hare, quite often for a week or more.
There has recently been an airport/local tax increase on car rentals, that can amount to $100 or more on a rental - all for the convenience of renting at an off-airport location.
I'm looking at some alternatives that might be more economical. Going off airport to a local rental office by Blue Line, for example might be a better choice.
If anyone has any ideas that might work at O'Hare, I'd love to hear them. We're all under pressure to reduce costs wherever we can!