Neither one of those cars sound like they would even cut your gas mileage bill in half. What are you getting with the RAM about 13-15?
So you'd have to buy something that gets at least 30 miles to the gallon to cut you monthly bill by $150.00. Then you may want to bank some of that money for parts and repair on a car with 100000 miles.
Also it would take you a heck of a long time in gas mileage savings to recoup your loss of $7,400. Don't do anything rash right now. At least hold onto the RAM until you can break even. Just my thoughts man.
Good luck on whatever you decide.