Hi @Daniel10299
I'm also an experience host with a nature related activity that has various options. There are two ways that I do this...
I have a 1.5 hour trail and a 3 hour trail, so for those I have two separate listings as they are quite different. The first 1.5 hour is the same, but then on the longer trail, there are the "upgraded" add-ons. (The 1.5 hour trail is a horse ride in a wildlife reserve, the 3 hour trail is the same, plus a ride through neighbouring vineyards and wine tasting).
For my 1.5 hour trail, I have now introduced a sunset ride - so the same experience, just at sunset - which I price a bit higher than my regular morning trails. For this, I just set the price higher when I create the availability on my calendar for the evening sessions. So both are on the same listing, but the morning rides have the regular price and the evening rides have the higher price. I know this isn't the same as an "upgrade" though so I'm not sure if it will be appropriate in your situation as you can't really specify different add-ons on your higher priced one doing it this way if it's a completely different experience which may need it's own listing.