Yeah, my bad. Still, I think it's quite expensive. If all they are offering is some simple runtime stats, then a 15% surcharge on the cost of a small instance is pretty expensive. If you have 50 instances, you're paying $540/month just for monitoring.

That is close to what it costs to run a single instance to collect all your statistics

Assuming you need a completely separate instance which couldn't do anything else but monitoring, which is unlikely to be the case.