Why will he sell the phone for 50% of its price? That doesn't make any sense.
Also, if the phone was stolen at customs then WHY did the buyer claimed he actually received the iPhone? Again the complain was that the iPhone he received was not working correctly NOT that he didn't receive the iPhone.
Because Ukraine is at war with Russia, 15% of territory and few major cities are lost, so salaries are dropped by 2-3x. Market for iPhones is low. This is why he is buying phone in USA instead of local seller.
As I can see, business of repairing of old phones is just overloaded, because most of people have no money to buy a new smartphone.
I have no idea why he claimed that. Maybe it's just Google translation made wrong.