I think one of the theaters around me has free refills on large popcorn (I might buy food once or twice a year at the movies so I'm not sure about the ins and outs of the concession stand) but you definitely don't get to bring the tub back the next time.
I live in suburban Philadelphia and the non-matinee tickets are $10 or $13 for 3-D. Though there is a real dump of a theater in the area that charges $8 a ticket (though that's about $7 too much for that theater).