A quick look suggests over $2,000 to rent the car with a one-way. One option would be to extend your trip by a week and choose a more circuitous route to visit some other places on the way back and then just return the car to LAX. Or see about hiring someone to drive the car back for you, particularly if you have friends or family in the states they'd probably be happy to do that and see some more of the country as well.