The price might suffer changes when arriving in this screen because the system makes a new Fare Quote for the selection made in the previous screen to offer the most accurate price possible (e.g.: one thing that might happen is that the new fare selection might incur in additional taxes which is only detected when the fare quote is made). Whenever the price (subtotal or taxes) suffers changes the info "Price was updated!" will appear.
Img 1: Screen 1 has a new price due to the change of the first segment fare and screen 2 shows the Price update when passing to the Fare Quote screen