Sprint-owned Virgin Mobile isn't just going to be celebrating the launch of its prepaid iPhone 4 and 4S on Friday. According to Bloomberg Businessweek, it's also going to be opening its first ten retail stores. The stores will open in Chicago, with a nationwide expansion possible if they do well. This would move the company away from its current sales model, in which Virgin phones are placed in other stores like Best Buy. Based on an interview with Sprint CEO Dan Hesse, the retail stores may be an effort not only to make the iPhone more visible but to move Virgin away from what's seen as the budget market. "There’s a misperception that the prepaid market is only for people that are economically challenged," he said. "That’s not the case. Our expectation, based on preorders, is that the iPhone will do very well on Virgin." Cricket, the first prepaid carrier to offer the iPhone, started selling it late last week.