^ SAC is 110% legit
one of the main rules is that you are not allowed to flip items from SAC and sell for a profit. so when selling an item, people will usually state that they did not purchase it from SAC in order to sell it for a higher price than the SAC price.
and if you were not aware, SAC is part of the backcountry.com family, which has one of the most legit customer services ever for a "big internet company".