This is what one of the articles says about the drug pricing.
By selling medications to Mainers at prices patients pay in Britain — which negotiates drug costs under the publicly funded National Health Service — Great British Drugstore can offer steep discounts, O’Brien said.
For example, Great British Drugstore markets a pack of 28 40-milligram pills of Lipitor, a cholesterol-lowering medication, at $108.40. The same pills cost more than double that at pharmacies including CVS, Walmart and Walgreens, according to the site.
So it seems to be as you say, Needmoresleep - they're taking advantage of the NHS negotiated rates for the drugs. But the one in the example clearly isn't something you'd be able to buy for less than the cost of an NHS prescription.
Anyway, it looks as though the profits from this particular venture won't have been great, since Maine repealed the law allowing drug imports early in 2015.
bangordailynews.com/2015/02/24/health/judge-overturns-maine-law-allowing-prescription-drug-imports/
Is that about the time GenderGP was set up?