I had assumed that Sharee knew a guy. Even I can't turn a profit with skooma despite how many of them I steal in any of my ES games. I think of it kind of like how one deals with excess ore in Skyrim; there's someone who's willing to buy it for a full price as long as you're willing to do the work of getting it yourself. I make a tidy profit on ebony this way until I get my smithing high enough to utilize it.