Have you wanted to try using MongoDB Atlas for learning and/or prototyping? Have you thought about moving your data to the cloud? Has the cost been a deterrent?
Today MongoDB has announced a new cluster in their Atlas offering, the M0. It allows users an excellent, cost-free, way to get started using MongoDB as a data source in a cloud environment quickly and easily.
With the M0 cluster one can start a free 3-node replica set to get started and then, using the amazing Atlas features, scale up the environment as needed. Atlas is a great cloud service which incorporates many features such as built in security, backup, and high availability, to name a few.
It you haven't tried it yet, I would highly recommend it. https://www.mongodb.com/atlas