I recall it being in the $75 range, but it's a one-time purchase. On future trips, Mickey updates!
I've had mine for over a year now, and still take him out to play when the kids aren't looking!
He can get annoying, however, when he gets stuck in reminder mode! While waiting for the fireworks, he'll say something like, "I hear the line is short for Space Mountain, why don't we head on over." Nice idea, but after the fifth or sixth time, you just want to say, "Shut up, Mickey!"