I've booked a refundable and upgraded WBC fare from TPA to NRT via MSP and DTW. The ticket came up at $3770 plus 15k miles. Okay, fine.

Recently I considered going to BKK instead (which always has a plane change in NRT). So I priced the same thing out and discovered some odd pricing.

When I run the same dates to BKK I'm getting fares in the $2000 range (plus 60K miles) with WBC to NRT and economy to/from BKK. This is interesting to me because I could still do WBC to NRT and just not use the BKK economy leg.

This pricing just doesn't make sense to me (not that NWA pricing should of course).

So...

Can I book TPA/BKK flight (and use it to just go to NRT at $1700 less) and not do the BKK sections of the flight? I'm guessing I could get away with this outbound, but not return since I can't check in and fly the first leg out of BKK to NRT?

Any suggestions?

thanks!