Are black marketplace drugs banned to boost pharmaceutical industry dependency?
Yes and No.
The No first. most pharm compounds are dangerous, contra-indicated, or even toxic at the wrong dosage levels. you are also looking at the certainty that there may be contamination of the pills surrounded by divorcing them and/or getting the wrong compound into the bottle. so on the no column your looking at correct dispensing of your drugs, QA, and a bit of friendly banter at the pharmacy.
The Yes. this is more of the Grey Market series not quite the black. Where you may purchase a prescribed drug from a foreign pharmacy for a lower price. some government have price controls on the cost of a secure pills, where as surrounded by the US it is set by the Market forces. Spain and the UK have fixed to semi-fixed prices for script, and sometimes a lot cheaper to run through those systems if you have access to them.
as for the straight black marketplace with Jimmy on the corner selling what he call Cipro... I wouldn't take it no situation how cheap it was.
The structure of what's vetoed and what drugs have mediocre restrictions is a vain governmental attempt to save fools from themselves.