I feel for you man, $80 would not make my day.
I'm not defending them or anything, but if you look at the Hudy parts sheet, you'll noticed that all items with a quantity of of two or more have a parenthesis around the quantiy. It appears that all other items without a quantity in parenthesis are assumed to be one in quantity. I would not have interpreted it that way, had it not been for your post.
I can only assume that by "Set", they mean it comes with the shaft and the outdrive.