Affordable, fun things to do in Whistler?

Going to spend a couple days in Whistler with a friend on Wed/Thur/Fri, neither of us are very familiar with the place. Anyways, we are wondering if reddit has any suggestions of fun things to see and do while we're there!

We're already planning on taking Wildplay's Monkido course in Whistler. We're also planning to stop at Grouse for the afternoon when we drive up there from Vancouver. We're looking for entertaining activities at $50 and under. We'd love to go rafting or ziplining but its just too expensive. Both of us are moderately fit but we're not looking for anything too strenuous like difficult hikes. Are any mountain hikes accessible without paying $40 for the gondola?

Places to see? Places to eat? Things to do? Little known secrets of Whistler? Let us know!

Thanks, Reddit!