"Someone might have a big group going camping . A company may want them to keep on hand for emergencies. If the prices are cheap enough, even at retail, they might want to resell them on eBay. "
If they're going camping, it's likely that there won't be cell service. A company can buy the things at wholesale. As for eBay, I just went there and checked. All the prepaid phones there are selling for less than they cost at Walmart.
Care to try again for a good reason to buy 100 prepaid cell phones at retail prices?
Mostly, though, I don't think it's necessary to come up with a "good" reason to own something legal. I have a friend who owns over a dozen guns locked up in his safe. Does anyone NEED over a dozen guns? Is there a good reason for someone to own over a dozen guns? It doesn't matter. If he purchased them and is using them legally, he is following the law and shouldn't have to be subject to an interrogation by law officers to defend an action which needs no defense.