Insping is cheapest website monitoring tool and it has No hidden costs. Checkout Insping Pricing and know how much cheaper it is then Pingdom.
Unlike Pingdom, Insping allows you to add multiple users to each organization and application. Restrict access by sorting users as ‘Admin’ or ‘Staff’ and assign them to specific organizations or applications.
Insping's Realtime Dashboard is more informative then Pingdom's. It presents current status, statue change time line, preformence graph of all your checks in sigle place.
Unlike Pingdom, Insping focuses on simplicity, Its limited and prioritized set of functionalities/features making its interface cleanner and intuitive.