I think newbies with no connections will buy legally. Many experienced users though will buy the cheaper product: they have already shown an inclination to buy from black mkt, so it's hardly a second thought. Poorer people, where every dime counts, will buy the cheapest, ie, black mkt. But if Bill Gates uses, he will buy legally: it would not be worth the trouble.
There will be an incentive for black mkt prices to be lower: otherwise, everyone will buy legal.
There will be an incentive for black mkt prices to be lower: otherwise, everyone will buy legal.