Let's say your price option is 1000 rubles per place per day.
But you want to charge $2000 per day when customer books 3 places.
Thus, you will need to create a discount of $1000 per day.
It should only be valid for bookings of 3 or more places.
To do this, create a pricing component with the formula:
-1000 * [INTERVALS]
And set the minimal shares constraint of the component to 3 shares.
In this case, when booking one or two places, the discount will not be applied.
See the example in action: