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Join Date: Sep 2009
Location: Minneapolis: DL DM charter 2.3MM
Programs: A3*Gold, SPG Plat, HyattDiamond, MarriottPP, LHW exAccess, ICI, Raffles Amb, NW PE MM, TWA Gold MM
Posts: 102,617
This seems like a case where it would be wise to pay for the third bag at $25, perhaps with a small discount, during OLCI rather than risking an agent insisting on a much higher charge if the upgrade does not happen before the gate.
Can you use miles or SWUs to upgrade in advance, which requires Y B M H Q K fares? This would secure the higher baggage allowance.