Buying the bundle is cheaper than buying a plugin and then upgrading to the bundle. So, for the best possible deal buy the bundle outright.
How is the bundle upgrade price calculated?
First thing, since the bundle price changes with new products, the exact price divisions change also. This article is a guide, since the cost of the bundle upgrade does not simply remove the cost of what has already been paid.
As an example, in the Pro Effects bundle, we calculated that Infiltrator is approximately 25% of the value of the bundle, so you'll get roughly 25% off the total bundle price if you already own Infiltrator.
Whereas Duck is approximately 5% of the bundle, so you'll get roughly 5% off the bundle price if you own Duck.
And if you owned both you'd be getting about 30% off the bundle price.
This is why the amount on your bundle discount is not the same as what you paid for your existing purchase(s).
Hopefully this provides some clarity, still, if there is any further information needed, please feel free to contact our support at the address below.