I'm trying to figure out the most efficient way, as a Premier member, to fly Business internationally. I've got an admittedly weird itinerary: SFO-DUB / NAP-IAD-SFO. It appears that sub-B-class tickets are around $1500, but B- or Y-class tickets begin around $3300 -- more than double the price of the non-refundable fares.

Is the best way really, then, to buy the sub-B-class tickets, and pay 20k miles per leg I want to upgrade plus a $550 per leg co-pay? That seems... exorbitant. Do the benefits of being Premier really not get me anything, here?

Ideally, I wouldn't book the entire fare with miles, because this is a business trip (despite which there's a cap on how much they'll reimburse me for the flight, and it's well below the cost of a business ticket, unfortunately).

Thanks for any tips and advice!