I think the time spent flying is well worth the money on commercial flights. Driving is six or seven hours, very much not worth my time especially if the ship boards early. You miss the early boarding hoopla. And on the return, you have to DRIVE home after exhausting yourself on the cruise, or relaxing yourself into euphoria. Either way I wouldn't do it.
I'd do commerical air. Actually I am doing commercial air--leaving monday!