re: Advice on renting a car to drop off in another location

Look for deals through national (who I use) or any other company you are loyal to. I rented one in Seattle and dropped off in San Francisco a week later for only $240+ tolls. They had some offer that was get a free day with a 4 day rental.

Another thing to look into that might be a pain in the arse is to do a drop off and pickup a new car in one of the cities in the middle. That way the one way fee won't be $500.