Entry to the museum itself is free, entry to the butterfly garden is extra. They do charge parking during the week, but on weekends that's free. When we were there, they had another exhibit called "CSI Bugs", which we didn't visit. If you're in the area, it's easy to find and a good stop. We spent a bit over an hour exploring. It's off of what I would call a 'main strip' with food and shopping in the area.