Shocker….
Splunk no longer publishes pricing information so prospective buyers should contact the company for a quote. Splunk offers legacy ingest pricing in addition to entity pricing and workload pricing. Workload pricing is being positioned as the more value-oriented plan. Enterprise ingest rates had started at $150 a month for 1GB of data a day, with discounts per GB as volume increases. AWS also has some pricing info.
https://www.esecurityplanet.com/products/siem-tools/