If the quality we're interested in is "being Harvard," then no, Harvard is not fungible. But if the quality is "providing a college education," the Harvard is extremely fungible in many cases.
People don't seek Harvard for the education only. They seek it or lots of things: access to wealth, access to knowledge and network, increased status, increased reputation.
Otherwise why would there be exceptional demand (and price) for harvard?
Otherwise why would there be exceptional demand (and price) for harvard?