It is worth splitting hairs because AT&T and Verizon are guaranteed to either make $75+/mo (it was $110 for my minimal minutes plan) for 2+ years OR a $200+ cancellation fee to make up for the cost of the phone.
You can buy a Virgin mobile phone and never activate it. You can stop paying without penalty after your first month. That's unsubsidised.
OTOH, Virgin USA may still be subsidizing it (by charging below cost), and just willing to take a loss if you never activate it. Since it only works on the Virgin network anyways, this isn't a risky gamble.