You can use tObserver with TYPO3 instances without any costs. Those TYPO3 instaces will stay free as long as the tObserver service is available, regardles of the fact, that you add non-free TYPO3 instances.
Non-free TYPO3 instances are billed according to our current pricing.
Non-free TYPO3 instances will be billed by invoice on a monthly basis. You only pay for TYPO3 instances, where the monthly usage is more than 5 days.
We will do our best to keep the service at a high availability. All server systems are monitored by our monitoring system.