I guess if you really need to save money. But I have seen Demo stuff get beat to shit. Guys don't care at all about them. I demo'd some Burton Maltiva bindings and someone else cross threaded the screws for the straps so I wasn't able to ride the bindings as I couldn't adjust them.
I would guess its a roll of the dice plus you are buying sight un-seen over the web. What guarantees or return policy does C-3 have??? would be my quesiton.