Question: Is there a server security service that offers a free option and flexible pricing based on server specifications and user count?

If you're looking for a server security service with a free tier and pay-as-you-go pricing that varies depending on server configuration and the number of users, BitNinja is worth a look. BitNinja offers a range of server security tools, including AI-powered Linux malware scanning, IP reputation monitoring and a web application firewall. It's aimed at shared web hosting, VPS companies and smaller businesses, with pricing that increases with server horsepower and the number of users. That makes it a good option for those who need something more modest, and its free tier is available for small needs.

Another option is LimaCharlie, which offers a SecOps Cloud Platform that combines endpoint security, observability, detection and response rules. LimaCharlie is for enterprise customers and managed security service providers, with pay-as-you-go pricing that discounts annual and multi-year subscriptions. It also offers a full-featured free tier with two sensors, so it's a good option for those with a variety of security needs.

Last is Sumo Logic, a cloud-based service for log processing, monitoring and SIEM. It uses AI and machine learning to help with log processing and cloud SIEM, and it's designed for developers and security teams. Sumo Logic has several pricing tiers, including a free option, and its credit-based pricing can be more flexible, accommodating many integrations with cloud computing services, containers and databases.