Drugs don't cost nearly as much to develop as the pharmaceutical industry would have you believe, between tax breaks and the amount of basic research that is done by both public and private universities; often funded by taxpayers. They'd have no trouble making the R&D costs back if they sold at African prices everywhere - they just wouldn't make beaucoup bucks doing it.
If they're so concerned about recovering R&D costs, maybe they could cut back on direct to consumer advertising and let the doctor decide what drug to prescribe. Like, you know, do his job? Those 1 minute spots for toenail fungus eliminator and quit smoking pills on the nightly news can't be cheap and they're on all the time.