This place isn't just for tourists. I've been a VIP member here for a few years, and it's definitely worth the cost! You get in to the special exhibits for free, and never have to wait in line. These exhibits are always great (Chihuly's in particular was amazing), and they are always putting on free films and talks to get people involved in the art scene.
The free section is worth checking out as well. So whether you're a tourist, or a local, don't forget to give this museum a shot!