They want to command $15/mo for their base plan. That seems very expensive. What do they provide that I can't get from a cron job that notifies me when my servi

They want to command $15/mo for their base plan. That seems very expensive. What do they provide that I can't get from a cron job that notifies me when my services are down? (Coming from the hobbiest or small project perspective, as, at work, we monitor our own stuff with health checks tied into alerting systems).