It all depends on your workload, access patterns, and data model. You can absolutely spend an arm and a leg making a system work using a RDBMS that would be si

It all depends on your workload, access patterns, and data model. You can absolutely spend an arm and a leg making a system work using a RDBMS that would be simpler and cheaper using a NoSQL store. The opposite is also true. When picking a database you should always consider the trade offs of the different technologies and weigh those against your goals and budgets. Sometimes is okay to spend more for a system that is just simpler to manage and use. Sometimes it’s not.