First off, if you take a look at the similar products sold at retail stores and compare it with the pricing on stores at country of origin(mainly US), you can see the amount of difference is substantial. These are the listed prices, think of how much the stores are paying the manufacturers for bulk orders.

The extra costs comes in when there is shipping and handling of good..etc. Just because the people outside of GNC/other retailers can get the products for a much cheaper price(still not cheaper than net costs advertised in US retail stores), does not mean it is fake/contraband.

I would classify a 'trustworthy source' as one that satisfies me in terms of the money I pay for quality of service and product I get; not the source that has the most numbers of stores nationwide. If one feels happy paying GNC dollars for their products then so be it, but pointing that the alternative methods out there to obtain supplements are fake and scam is immature by such reputable corporations.