I don't care what people do but stop trying to justify grey key market is legit. Just stop lying to yourself. Paying $20 for a $70 grey market key is no different then pirating.
They can be significantly cheaper, especially with Microsoft partner programs. Individual licenses are 20% cheaper alone in India. There's also tons of corporate & education program discounts for the 3rd world that gets milked. What they do is...
Gray market scam keys.. they buy keys from 3rd world regions where they're much cheaper, then resell them illegally / against the ToS/EULA. Every so often Microsoft does region matching and purges keys used outside of regions they aren't supposed...