So with a Full boeing 747 (probably a large overestimate), that's about 366 people (with wikipedia as source). At 10 minutes you're wasting 61 man hours (did I make a mistake? That seems way too large). Taking a low estimate on the value of people's time of about $10 per hour, you should be saving $610 to justify it...

Let's go with a smaller plane... My friend who is into airplanes tells me that 40 is a good estimate for shuttle planes from small cities to bigger hubs (30ish to 50ish, I just averaged them). So every 10 minutes you waste is about 6.5 man hours. Again valuing people's time at $10 per hour, you'd have to save $65 to break even (though that relies on pretty low valuation of the value of people's time).