Well, they’re sure not kids anymore since the movie was made 30 years ago (can you believe it?). But it’s Salem’s unofficial Official Movie and we’ll be watching it come October forever. The “kids” – Thora Birch (Dani), Omri Katz (Max), Jason Marsden (Thackery) and Vinessa Shaw (Allison) – will be making the Salem scene on October 20 & 21, on Friday at a costume bash at Bit Bar on Derby St., then at an autograph meet ‘n greet on Salem Common the next day. You’ll need to buy tickets to attend, and . . . it’s not, shall we say, cheap. But can you really put a price on magic? The three Sanderson sisters are not expected to fly in but in Salem, anything can happen.