"1/20th the cost of Harvard" is in the ballpark of what a super affordable undergraduate program at a US public university goes for.
To be sure, your cite lists annual cost of tuition as clarified in Methodology section language.
Their "average program cost" metric is also pretty meaningless; you either pay in-state or out-of-state rates---not some arbitrary arithmetic mean---so ~3x for a rough lower bound of what tuition alone will run you, and that assumes the unlikely scenario of no tuition increases during subsequent years of study.