If you are looking to provide the discount according to the no of person available, then group discount is the right feature to add.
WP Travel Group Discount module included in WP Travel Pro allows the admin to add the prices which can be offered as the group discount based on no of people attending the trips.
Admin will be able to add the group discount from the tab “Dates and Prices” of individual trips.
After that the user will able to see the discount price offered on the trip by clicking on the link “View Group discount” at the trip single page under “Booking” tab.
For detail information on this, please refer to the link of official documentation given below:
Also, if you have any confusion regarding the plugin then please contact us via our official support below: