A FlyerTalk Posting Legend
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
You might be able to use the $400 credit to purchase a (codeshare) flight on an AS partner.
Is that $400 per person or total?
You should look at your ticket price and calculate what the DOT mandated payment (in money) would be if it were officially an IDB.