I tried to buy an iPhone 5 retail from a corp VZW store a couple of weeks ago. The rep said, the sale "wouldn't go through" and phone couldn't be activated because the phone was "in high demand"??? That night I bought a phone outright on apple.com and picked it up the next day at the Apple Store...
I think there is beginning to be enough anecdotal evidence to at least suggest VZW stores may be limiting non-contract (new or extension) sales.
BTW, if you choose, many VZW phones can be purchased retail on Amazon with free-shipping and in some cases tax-free (not making a judgement on whether it's "right" or not, just pointing out reality). This makes the purchase much less than a VZW corp store or VZW.com.