Whether or not it's cheaper to drive instead of fly depends on the distance you're traveling and the cost of the flight.
If you're going to travel only 400 to 1,000 miles then it's usually cheaper to just drive your vehicle than to fly but driving takes longer to get to the destination than flying.
But when driving you get to see sights and take your time to get to the destination and you don't have to go through security.
If traveling less than 3,000 miles I usually just drive unless I have to arrive at the destination in a certain amount of time.
Driving takes longer but I like to stop and see sights and I love driving so it's not an issue.
But for people traveling over 1,000 miles it's usually cheaper to board a flight and get to the destination.