I agree. I thought the same. But endowment size can affect how much $ is given in aid, the size of classes, the professors salaries etc. So it can be a factor. For most people, they look at their options, the costs of each and then make a choice. In this case, the schools are pretty equal in terms of reputation.
In the OP’s case, the 100K is huge. So I doubt he’ll be weighing the endowment. LOL.