I've been looking at business class airfares from San Francisco to Warsaw Poland for travel this fall. The prices are going through the roof. Just for fun I compared the exact flights from SFO to Frankfurt and SFO to Warsaw. I then reversed the itinerary from Frankfurt to SFO and from Warsaw to SFO. The dates I selected was departing Sept 13 returning Oct3. Selecting the exact flights there was a big difference. The base prices and taxes were close. The big difference was the so-called international fuel surcharge fee which seems to be a below the line way to hike prices. I saw this with almost all the airlines I checked.

The SFO to Frankfurt cost on United/Lufthansa was $4,481 roundtrip. The exact same flights this time starting from Frankfurt to SFO was $3,792. a $689. difference.
The SFO to Warsaw cost on United/Lufthansa was $5,523 roundtrip. The exact same flights this time starting from Warsaw to SFO was $4,170.00. a $1,353. difference.

Again, this is not a United/Lufthansa specific problem. All the airlines I tested this with are doing the same. Looks like an airline imposed US itinerary originating fee.