Last week, the Dedham-based National Amusements, which operates Showcase Cinemas Worcester North and the Cinema De Lux in Millbury, started pre-sales for the one-week engagement of Hannah Montana & Miley Cyrus: Best of Both Worlds Concert in 3-D. “Hannah Montana,” for those who don’t know a child between the age of 6 and 14 (2/3 of whom watch or have watched the show), is a Disney Channel show about a girl, played by Miley Cyrus, whose alter ego is a pop star by night. The movie is a stitching-together of three concerts from the sold-out concert, tickets for which some rabid fans have had to pay well in excess of $1000 a piece. Tickets to the February 1-7 run of the show, which runs February 1-7 at both local National Amusements theatres, run a considerably more modest $15.00. Tickets can be purchased in advance online at NationalAmusements.com or by calling the (508) 853-4000. Please note that Prestige Tickets, passes and other discounts cannot be accepted for this special engagement.