There are pros and cons to Gouldings and tours. Trying to make this short (HA HA, I know you are all giggling at that)
Gouldings, full hook up sites, gorgeous campground, looking at the red surrounding you is special. It is a VERY busy campground. Call for reservations ASAP.
There is boondock camping JUST inside the Valley. Sites looked nice, although we did nothing more than drive by them. 8.1 Charlie has stayed there. No hookups, so, if hot??? Depends on your tolerances.
Actual visiting the Valley, by guided tour or self drive. Benefits to both.
Guided tour, they will take you places you are not allowed in your private vehicle. We took the Gouldings tour 4 years ago and We were sooo glad we did. Worth every penny!
This year, just weeks ago, we decided to drive the Valley in our own truck. It was so worth it. It was a totally different experience. We did, by the way, use 4 wheel drive getting up some of the hills, on the roads, because they have very soft sand that Jolly the truck slipped in.
So, if you can, do both, take a tour AND drive it yourself!
On my blog, Reflections (link at the bottom of my sig line here on MOC) there is a search box. Click to Reflections, go to top left corner, type in Monument Valley. Lots of photos from both years visits to the area, even tho I have not really done a lot with this years 600 plus photos!
Enjoy, it is one of the most awesome places!