The cost of NoSQL databases varies depending on factors like service provider and required features. Providers typically offer diverse pricing plans, including free options with basic functionality like MongoDB and CouchDB, suitable for newcomers. For advanced users needing enhanced features such as scalability, costs may rise significantly. Enterprise-level solutions like Amazon DynamoDB or Microsoft Azure Cosmos DB offer greater flexibility and scalability at a higher price range, starting from around $50/month for single-node instances to several thousand dollars per month for multi-node clusters.