One thing of course is that nobody knows what the prices in the various countries will be come May or whenever you're buying the ticket. Indeed, once the new members join OW (April? Later?) nobody knows if the OWE will even be the same product.

Adding in the access cost to origin points is part of the equation. I was going to start a trip in ARN in about 6 weeks until I realized it meant (for me) needing to pass through LHR more than I wanted in the course of the trip (once is too many times at the moment) so I checked the exchange rates and found that ZRH is around US$600 more than ARN. Since I was going to be in that area anyway (thanks Alitalia ) a quick train trip or car trip to ZRH, followed by an intercontinental departure, made more sense than flying to ARN and then flying to LHR (or MAD or HEL) just in order to get out of Europe. Mind, that was for me (and she) but YMMV.

In your case if you want to start in Europe and your two desired stopover points in Europe are TLV and DXB (watch the old passport stamps on that one) then you need to start in some city that you can get back to straight from N. America. ZRH-MAD-TLV-LHR-DXB-HKG...JFK-ZRH, for instance.