Oscar, its likely they will be dirt cheap as Australian produce is invariably cheaper after export than anything we find here. International trade is a funny thing.
I'm certain the KPs in the US will have been picked early and taste as zesty as a lemon!
They may just end up shipping the rubbish old Florida mangoes back to the US as mangoes like Keitt, Kent, Brooks and TA just sit shrivelling on supermarket shelves here.
Worst case scenario is you get Calypso, which will enchant buyers with their looks, but taste like freshly moistened newspaper...