In order to have an economy of scale, first you need scale. But Stanford does not stand out in terms of the size of its faculty or enrollment, certainly not to the degree it does in terms of money. In fact, Stanford has fewer tenured faculty members (832) than UC Davis (1,126):

https://www.collegefactual.com/colleges/stanford-university/...

https://www.collegefactual.com/colleges/university-of-califo...

There are diseconomies of scale too. My experience is mostly of UK higher education, but my feeling is that most universities are a bit too large for their governing structures, and are poorly run as a result.

I haven't checked the numbers lately, so I could be wrong by now. But while I was a student there and for some years after (administrators / (students + researchers + educators)) got worse at a rapid pace. It's hard for me to imagine that Stanford is the best marginal bang for more bucks.