If you are doing mostly highway driving the battery pack in a hybrid is going to be used very little, if it was something like a mail route or pizza delivery your pack might not last 300,000 miles.
The Toyota Matrix is coming down to your price range for the older models but their gas mileage is not all that great! mid 20's to low 30's.
Here is
the more advanced search on the FuelEconomy.gov web site, searching for anything between 1984 and 2011 that gets over 40mpg pulls up some interesting vehicles.