There isn't. Virgin Mobile USA started as a prepaid experiment by Richard Branson's British Virgin Mobile company. They leased spectrum from Sprint and launched a pay-as-you-go prepaid model in the US. It was fairly successful. But then Virgin Mobile pulled out (around the time the record stores shut down) and Sprint bought them up. So now Sprint owns the prepaid carrier VirginMobileUSA and just keeps the name.
My first carrier was Virgin Mobile USA. That's one of the reasons when I went to a full contract I went to Sprint. I knew from experience what sort of coverage I'd get on the network. I had about a decade to learn and travel with it.
The phone quoted is going to Virgin Mobile in the UK. VM USA doesn't have LTE. At least not until Sprint gets it first.