Generally there are always a number of tickets available at one particular price and when those are sold out, the next price category becomes available – usually at a slightly higher price. It can happen that there is only one ticket left at the initial price, and that is why when you try to book two or more tickets the total price changes.
Once you’re redirected to the airline or travel agent, the total amount for all tickets and passengers should be shown to you, and that is the final amount that you will pay. We recommend that you check this carefully before you confirm and pay for your booking.
As a search engine, Skyscanner doesn’t actually take any bookings or payments; instead you book and pay directly with the flight provider.