Comment by maxmorlocke

For a typical db.t3.xlarge instance, you're talking about 29c/hour vs 27.2c per hour. That's $157.68 as the total difference for one year's runtime, when the whole instance cost for postgres would be $2540.4 for the year, or about 6%. The larger the machine, the closer to parity. Given the absolutely small difference, I hope this isn't the dividing line in any commercial project.