Yellowstone / Grand Teton / Mount Rushmore - Number Of Days?

I wouldn't waste time going to Craters of the Moon if your total time is limited. It was the lowlight of a 15 week trip.
Devils Tower was great and I might return this year. Camping was cheap there. I really liked Rushmore. There is a federal campground a couple of miles away called Horse Thief Lake. Right on the main road to Rushmore. No hookups but nice sites and convenient location. $11 night for senior pass.
I liked the Southern campground in the Tetons better than the Northern one. It's near Jackson Hole.