The ammo for the virtual one is a lot cheaper. I met a gun collector who liked to play Call of Duty because it had guns he owned in real-life, but in real-life he could only use them at the range or in case of zombie apocalypse. I told him I played Team Fortress 2 and explained what it was and he said "I don't like fantasy games". So there are people out there who try to collect the real and virtual versions in pairs.