Rental rates compared for same company, same time period picked up at different locations in the same city.

Last weekend we were killing some time on a rainy day by going over scenarios for making our Seattle to Chicago road trip a reality. One of the largest costs (if not the largest) on that trip would be the rental car. It would require us to pick up the car in Seattle and drop it off in Chicago.
We found through trying out various dates and locations on car rental sites that the pickup location has the largest influence on price, much bigger than the length of rental or drop-off city. Instead of picking up a car at the airport of your destination, try taking public transportation or a shuttle into a central city rental office if it’s convenient. For example, with one company, picking up the car at SeaTac Airport nearly doubled the weekly rate as compared to receiving the car at a central Seattle neighborhood location. With most major cities offering transportation to and from airports via rail or shuttle bus, it’s well worth sacrificing the convenience of going directly from gate to rental counter if you’re keeping costs down.
Another thing to consider, the car rentals originating in major cities were much more reasonable than rentals beginning in smaller towns. You can forget about trying to get a reasonable rate in Kalispell, Montana FYI.