Oh sure- in 2004, a hamburger at an airport terminal Burger King cost 74 cents. Of course it did. And a full meal including a Whopper, salad, fries and a drink cost what looks like five dollars in quarters- uh huh, sure I totally buy that.
Come on. I've been in plenty of airports over the years. The prices are ridiculously inflated- after all, you're limited in your options, you're traveling, you're either in a hurry or you're stuck waiting for a delayed flight but (like Tom Hanks' character here) you really can't leave to seek cheaper facilities elsewhere. It's like eating in a sports complex- you take what you can get and you pay what they want to charge.
This scene exists because Hanks' character had three quarters and Burger King threw money at the producers. This being the case, it would hardly do to have the cashier turn a very hungry Tom Hanks away because he (obviously) lacked sufficient funds to buy ANYTHING on the menu- that would have been right up there with burning an American Flag. I mean, this is Forrest Gump and Captain Miller- he fought in Vietnam AND World War II! And when Hanks' character has five dollars, he's going to go right back there to Burger King where, instead of getting that hamburger and MAYBE a small soda, he's going to be handed what would cost $15 at a typical strip mall Burger King or closer to $25 at an airport terminal BK.
The only realistic part is that Hanks keeps rushing back to BK several times over the course of the day to ravenously gulp down the garbage they serve up there- because the stuff is highly palatable, hyper-processed, low-nutrient and extremely addictive Nothing that will leave anyone extremely hungry within hours after consuming it. Hanks being trapped in that terminal for months is kind of a metaphor for the rest of Burger King's customers, except they can't see the walls they've created for themselves with every trip to the Drive-Thru.