That's why it was funny that Turkey was ostracized for buying Russian/Chinese SAMs ( was it S-400 last or a Chinese version). What else could they possibly buy? The Patriot system isn't even close, and doesn't seem to be working too well for the UAE ( but then again we don't know how S-300/400/500 would deal against drones and light missiles)
My guess is that Russia doesn't have that many S-xxx missile systems, and further that they are much more expensive than the Turkish drones. I imagine they're keeping their powder dry, against the risk of NATO planes appearing over Ukraine.