diffrent prices for diffrent options

hey, I want to add two fields
one field will have some locations as dropdown items with a speicific value assigned to each of them when a user selectes any of the location dropdown item (in my case TAXI TO is the field label) they can see the vaue say 45$ in the payment field. okay
second field is passengers field (in my case adult seats is the label) it have a dropdown with dropdown items of 1 2 3 4 means how many passangers i need to pickup and deliver to a specific location but the problem is each location have diffrent prices and diffrent increment charges per passenger
means ( charges for 1 person from airport to club is 50$ but if he got a friend with him the charges will add upto 10$ more and on the other side charges for 1 person from airport to casino is 100$ but if he got another friend with him the charges will be add upto 150$)
see diffrent prices with diffrent pax(per passenger) prices for each locations
how can i do this?

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