Let me just say that this is a beautiful piece, I would definitely wear something like this. Let me also say, that yes, it is definitley “in sellable condition.” Although there might be some chips in the turquoise (I cannot see them in your picture) I don’t think that it should effect the value too much. Matl Salas is a very collectible maker, and I think you should have no problem selling it. Here are some Matl Salas pieces that are currently listed on eBay, no bids.
Now, just remember that those are asking prices. Personally, they seem rather high to me. Alternatively, here are some pieces that have already sold on eBay.
Those selling prices seem a bit low, but the asking prices I feel are very, very high. I cannot tell how big or small your brooch is, which will impact the price greatly. Tentatively, I would say your brooch is somewhere in between, until we can see it’s size.