I've been at the receiving end of Elastics selling tactics and pricing. Elastic is the new Oracle was my conclusion. IIRC the pricing was along the lines of $12k per CPU Core or GB of RAM. Straight from the nineties.
In my experience it was that by Node regardless of how many cpus or ram the node had.
Regardless very expensive.
And Mongo is something similar as well. Just running single instance (on infrastructure that you pay for) might cost about 3k or more per month.