Henry's is on backorder for about 4+ weeks for delivery on the kit.
It seems they do not charge untill they are ready to ship which means yesterday's exchange rate may not be applicable. The USD to CAD could swing either way by the time the order is ready to ship. Last week, I paid $2 more in USD after everything.
Have they already charged you? What does the online order say?
EDIT: Also, how about currency conversion charges?
Wow... i never got notice that they are waiting on stock... where/how did you find that out?