> I'd be interested in a data point on how much a free db could help save

Database companies price their products by how much they think they can extract from your business. That's why they're mostly priced at free or some nominal cost for the first few years, and then several million dollars per year afterwards.

Without a doubt higher. If you pore snake oil on your database it always slows it down a little

free maybe. The real point being that it is one that works. A big part of the financial but also the entreprisey world in general have never left the 80s/90s. The idea of scale does not exist.