I have about a month off, and would like to visit Cambodia, Thailand, and Tokyo or Beijing. I'm tall, so 13 hours in economy is going to be horrible, but I might do it. I was ideally thinking of flying non-stop NYC to Tokyo or Beijing, and then figuring out the other legs later on. But likely spending 2 days in whichever city (Tokyo or Biejing) at each end of the trip, so that the flights aren't so bad.

Unfortunately, Kayak is telling me that NYC<->BKK is $1k, while the same flight (minus the onward leg to BKK) is $3k for just the NYC<->NRT. This is madness.

Will I have issues if I book the NYC<->BKK and just skip the BKK legs? Can I not use the return portion? How can I book a flexible trip most cheaply, without spending hours trying to trick the airline's insane price discrimination, and without running into rules I don't know about, like forfeiting return tickets if you miss a leg of travel?

Thanks so much for any and all advice.

P.S. Any recommended airlines for NYC<->NRT or NYC<->PKK? Flying economy, tall, would maybe upgrade to econ plus or business if the price is somewhat reasonable, but this is paid out of pocket, not buy a business. Thanks!!