Originally Posted by
BearX220
Supply and demand. There is more traffic between Chicago and Bucharest, with more airlines competing, so prices are lower. Less traffic between Detroit and Bucharest, so prices are higher. The fact that the Bucharest-Chicago trip you're considering involves a plane change in Detroit is immaterial. Airline sell tickets from point A to point B, without regard for the route taken to get there.
Absolutely not. Google "hidden city ticketing" to see what happens. The airlines regard this practice as theft.
Not "without regard for the route taken to get there." There can be enormous differences in prices for nonstop flights versus connections. In addition , certain routings can be more expensive for various reasons, for example on DL, compare SFO-LAX-JFK (D1 service) to SFO-MSP/DTW-JFK (regular FC service).