Sections priced apart
The front three rows as a ticket type of their own.
In the paid plans
Read the manual
Seats are grouped into categories: stalls, balcony, circle, or whatever you call them. A category is a colour on the map and a price at the checkout.
That is how the front three rows cost more than the back without becoming a separate event, and how the buyer can see the difference before they choose.
More in Seating
Draw the room once and sell the chair rather than the number.