We all know it's really hard to get good pricing and cost information.
Please share what you can so you can help your peers.
Spring per se is Open-Source based on Apache 2.0 Licence -- which states -- "perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare Derivative Works of, publicly display, publicly perform, sublicense, and distribute the Work and such Derivative Works in Source or Object form."
That gives you freedom for using the product and change the product to suit to your need. You can think how would Spring Monetize that's in the following forms:
1. Support Subscription: Premium would offer Global, 24x7 support for over 40 Spring projects, plus OpenJDK and Tomcat;
3. Infrastructure -- like if you run on VMware Spring Runtime -- there are several offerings on Tanzu -- Kube on top of VMware. -- This development happened after VMware acquired Spring Source; Fortunately they didn't let the community down by changing either license terms or vitiating the open-source nature of the product like in the case of other open-source projects hosted by Sun Microsystems.
It's open-source software, so it's free. It's a community license.
This is an open-source product.
Spring Boot is free; even the Spring Tools Suite for Eclipse is free. I advise others to use the cost savings to invest in Postman Pro, and to use that product to create and run suites of integration testing, whenever changes are made to the code base. I even advise moving unit testing to Postman Pro test scripts, which can be run by testers, in addition to developers. In this way, zero-defect applications can be deployed and supported.