Replying to Cheapest and Closest Place to Camp near Timberline

I know its still a little out of season for camping, but I'm planning my trip to hood for this June and i'm curious as to where the most recommended place to camp would be. I don't need hookups or anything, just a square of land where I can plop a tent. And also just a side question, are there any multi-day tickets available for Timberline in the summer? Or are you stuck just paying for the daily ticket price?
Thanks in advanced for any help.