This has benn going on for years here in NYC with Asian people lining up to buy phones for full retail. It's true though, none of speak hardly any English and pay with either cash or Apple gift cards.
Apple can't really put a stop to it though, I mean they are buying it for full price just as anyone else would. What they do with the phone is their business. I do however dislike scalpers and resellers for this very reason. Hurts the person who genuinely wants to buy the phone for personal use.
i hate scalpers in general. ESPECIALLY my own race [asians] they tend to be the ones who are very quick to rush on an opportunity. hurts the consumer who wanna pay original price.
the only way is to not attend to scalpers then they will feel boredom and annoyance.
but then again if the consumer is so desperate then there is nothing i can do...
for me i can wait for 2-3 weeks for iPhone X delivery as of now. My current iPhone 6s plus still works like a gem but now it feels big after handling the iPhone X in store
tl:dr ; don't give scalpers attention, you will piss them off by not giving them your attention , and You win, they lose out.