Of course that we should count add-ons both for Gomes and Denis.
But, from what I have read here, it seems that Denis will reach his conditions, since he is only supposed to play and his addons are not related to CL trophies and similar.
So, even if win nothing in the next 3 years, we will need to play additional 10M for Denis ONLY because he played 100 matches for Barca.
About Gomes, he has conditions like winning trebles, winning CLs, and being a BallonDOr (Iirc).
I wanted to say, if we'll win La Ligas and Cdrs, but not CL, we will pay a lot of additional money for Denis and almost nothing for Gomes.
Gomes will cost us a lot of additional money if we'll treble after treble.
So, imo, total fee for Gomes in the end will be closer to an original transfer fee (35-40M), while a fee for Denis will rise a lot regardless of our trophies (12-15M, based on whether we count or not transfers between Barca, Sevilla and Villareal and who knows what has actually happened there and who paid how much).