This story just proves it again - if someone’s selling you Bitcoin at a discount, especially off-exchange, you’re probably not buying Bitcoin… you're buying risk.
Why would anyone part with the hardest money on earth for less than market price, unless they are hiding something?

That’s sound logic because of the existence of money laundering and wallet hacking, we are all advised to check the source of the coin, and the reputation of the seller, if you don’t have these two, you’d better buy Bitcoin in a reliable exchange to protect yourself from a dirty money route.
If the seller cannot provide valid reasons for selling at a discounted price, then you should be suspicious.