> Side note, I'm surprised that these types of scientific surplus stores have lasted longer in the upper Midwest than places like silicon valley or near bell labs in NJ.

Real estate prices are a big factor. Rents in silicon valley, and I suspect NJ have increased much more than midwest rents. Even if the store location is owned, when the business owners are looking to retire, it's then a question of selling the business with the space or closing the business and selling the space by itself, and the value of the space is probably enough that it doesn't make sense to tie it to a business.

Add a bit of reality that manufacturing and the surplus it generates has mostly left silicon valley and NJ, and it makes more sense to have such a business elsewhere.