Horseshoe Bay would be a good mid point between downtown and Whistler. Hotels should be cheaper in Whistler by the time the regular Olympics are done, as should the hotels in downtown.
I don't get in to town as often as I used to, and when I do, it's usually just for visiting family for a couple hours.
I'd actually suggest staying right in the downtown core at one of the hotels for a couple days, then in Whistler for a couple days, and then, on your way home check out White Rock for a night, or afternoon.
Keep us posted.