When you go on a web site (hertz, budget etc) and make your reservation, the price they display does not include the insurance; add about $29 per day to calculate the total price. and don't foget to add the taxes on top of that.
If you like going out and spend your evening in a restaurant, don't forget that in U.S. tipping is mandatory. The waiters are actually living out of your tip. The standard is 15-17% of your bill, if you really liked the service, 20% is common.