www.funagain.com excellent service - however they FedEx everything so the postage is often more expensive than the games. They have 'Flux' but not 'Mind Trap' though.
I generally order about $100 worth of games each time and the shipping costs are about $50. Nevertheless just buying one copy of Clue/Cluedo at the local international bookstore will set you back about 4000 yen.
Current favorite games are Frank's Zoo (excellent for plurals practice) and Rat-a-Tat Cat (even my adult students enjoy this one).
PM me and I might be convinced to split the postage costs on a joint order (yes I know they'll be additional postage to send the items within Japan but it still might work out cheaper overall)