In Events.
Add the ability to set tickets for individual attractions (as currently is the case), but also add “extras” to those tickets.
This is useful for large events, where customers can purchase entry to different zones at different prices, but can also purchase tickets for individual optional attractions within those zones, or wish to purchase optional event merchandise.
And also add ability to set a common pool for “extras” available in different ticket categories or set them correctly.
In an example of festival:
Entry to the small stage zone costs €150, and to the large stage – €250.
On both zones are are available souvenir photos (the photo booth is located between the zones and has a shared capacity – therefore, the total number of available tickets). However the Festival T-shirts are included in the ticket price on the large stage, while they must be purchased separately on the small stage.
Another example - business or photo conferences
Entry to the conference itself costs X Euro, but possibility to attend on limited chairs additional discussion panels cost extra.