They are nice as a backdrop and decoration, but to be honest I feel like you could have the same visual effect by putting up any random assortment of Silver Age comics, including those that are not particularly valuable. In most shops I've been to, the comics up on the wall were usually way overpriced by my reckoning. I understand brick-and-mortar stores can't compete with eBay and online stores on price, nor do I necessarily expect them to, but they also can't price their books in complete ignorance of them either.