Here's the page listing all the base packages. Note that the buttons for Gold and Portfolio are greyed out. I've bought those packages (in that order). But all the other ones are still orange. It should grey out the buttons for any lower packages than the one I own, since they're all subsumed in the higher one. The one exception to this rule would be Original Languages which as I recall does not fall precisely "between" two other packages, in terms of being a smooth upgrade path between the lower and the higher one.
