@MotherOfDragons Rugg’s surveys the admissions officers for grad schools, asking them to rank the undergrad programs from whom they are considering applicants. So it is their opinion, but since they are the “gatekeepers” for admission to grad programs, their opinion matters.
As far as cost, it is $25 to download in a PDF format. Considering tuition costs, that is the proverbial drop in the bucket. I donated my copy back to my son’s school after he made his college decision.
Good luck!