Originally Posted by
whimike
The taxes jump quite a bit when trying to do a return booking!!

Yes, about US$280 and $380 in fees/taxes per for my C awards/upgraded tixs on United for the return.
BTW, this is yet another time where I booked two one-way awards on different airlines. Kudos to both BA and United for allowing that. Among the many flaws of Delta's program is not allowing one-ways (well, technically they allow one-ways, but for the same price as RTs).