The rental price listed on rental portals like AirBnB and Booking.com are higher than the rental price listed on the Sun and Sea Holiday website.
This is because the rental portals also charge a commission.
Rental portals charge commission on the rental price but also on other costs such as cleaning costs and service packages (bed linen and towels) which means these costs have to be increased.

If a rental portal charges a 15% commission then prices must be increased 18% to cover the full cost.