Duke787

Award ticket routing often breaks routing rules that paid tickets may have in place in the lower fare buckets.

My guess is DL/AF/KL/VS don't have routing rules that permit you to fly BUD - AMS - LHR - LAS on a single ticket -- it probably requires end to end ticketing.

AFAIK, VS and KL don't have a codeshare for something like this. Why would KLM allow someone to fly BUD - AMS - LHR - LAS instead of flying BUD - AMS - XYZ - LAS on revenue neutral DL/KL metal? It may be coming once the JV is finalized with AF/KLM/VS/DL -- I think it just finally got regulatory clearance a couple days back so my guess is no codeshare routings via LHR have been put into place yet.

So when you actually go to ticket it, I bet DL is giving you full fare pricing on BUD - AMS - LHR and then LHR - LAS which can definitely get to $10k very quickly on one way J tickets.

Awards don't have this problem since DL lets you combine partners solely based on award availability without similar restrictions (though we are seeing similar restrictions pop-up on all DL routes where OW tickets cost more than half of the RT ticket).