I agree you have to put a perspective on it. I too was concerned when hearing the gas price hike -- seemed like it would be 50% more expensive than our gas prices on our last Disney trip.... hmmm, would flying be cheaper?
Well -- with a family of five and the nearest "true" airport at least 70 miles away, you do the math! The price-hike in gas might take us from a budgeted $150 in gas to $225. Also add in a hotel room on the way down and coming back, along with extra food during the trip down and back. HOWEVER -- Cheapest airfare was $200 per head (TIMES 5), and then we would need to add some gas $$ to get to airport, those lovely airport parking fees for 12 days, and transportation to WDW from the airport.
Even with the gas hikes, I just honestly don't see how we can ever justify a flight versus driving, with the size of our crew and at those rates. And if wear on our vehicle were an issue, I think we could probably rent a vehicle to drive down for the trip and STILL come out cheaper than flying. Driving can really stink sometimes from a time and fatigue perspective, but honestly, it's still the cheapest, even with the outrageous gas prices.