I've never been in the sales room. I've heard from multiple corps that Splunk is quite expensive. I've been to one place that ran its own Elastic stack, which was a bit of cost in its own right because they had to run all the infrastructure and storage themselves, and had two FTEs whose main job was keeping the thing running. I don't know what Splunk offers from a UI/features perspective that Kibana couldn't do.

I agree (as the owner of an elastic stack at work). A second FTE sounds like a luxury though..