Education inflation is currently running about 7-8% (source). I don't have any data on what this rate was a century ago, so I'll just assume it's been constant. The general rate of inflation in the US for the last century has averaged about 3.2%. This means that education inflation is about 4% in real dollars. If you compute 1.04^100, you get about 50, i.e., about two orders of magnitude in a century. This is pretty much the size of the effect you describe in the cost of starting up a new university.
The deeper question would be why inflation in certain areas, such as healthcare and education, is so much higher than the general rate of inflation. I don't think economists have a universally agreed upon explanation for this. My understanding is that there are several explanations, all of which are probably true:
Goods and commodities can always go down in value. The cost of a book, for example, is many orders of magnitude less than it was in the middle ages. But services can't become cheaper without bound. Services are provided by humans, who need to live. Therefore there is always a tendency for the non-service part of the economy to shrink in proportion to the service economy.
In most countries, healthcare and education are government monopolies, or nearly so. In such a setup, people are using something that they don't pay for, so there is no tendency to restrain their use of the resource.
In healthcare and education, people don't or can't make normal decisions on cost and value. For example, if the price of Greek yoghurt gets too high, I can decide to stop eating Greek yoghurt. But if education gets super expensive, I don't just tell my kids not to go to college.