Actually, that has nothing to do with the question.
The issue is that if you buy base Civ5, G&K and BNW, you are still missing all little DLCs released up to date, and only way to get them is by buying them with full price, or buying whole Complete Edition.
When Civ5 Gold was out, they had great gold upgrade option, which was a very cheap way get get both G&K and all mini-DLC released up to that point, if you already own base Civ5.
Now it is unfortunately gone.
P.S.
I guess this is sort of big issue for users that bought Civ5 with all expansions in recent humble bundle.
They will be missing all small DLCs, and those DLCs are more expensive then whole bundle if bought separately.