The myth of selling BTC to fools locally is laughable. Nobody is stupid to pay more for BTC than market rate I would believe.
I've done just that, might only have been a few thousand dollars worth, but a 10-20% premium was still worth having.
Did you find a fool, or someone using the coins for illicit means?
For many people actually buying BTC is a huge pain in the ass. If you were only buying a couple hundred dollars worth of BTC it might be worth your time to just pay someone $40 extra to get you the BTC, especially if it also saves you a few bucks in exchange fees.