Database spend simulator for pre-launch architecture decisions

The sharpest version of the cost problem happens before any money is spent — when a developer or small team is choosing which managed database to use and trying to figure out what it will actually cost at their expected scale. At that point they have almost no leverage: once you build on DynamoDB or Timestream, switching is expensive and painful, so the cost model you're locked into was chosen when you knew the least.

The gap exists because nobody who sells managed databases has any incentive to build an honest cross-service cost comparison tool. Each vendor's pricing calculator only covers their own service and optimizes for making the number look reasonable. Independent cost calculators that exist are either outdated, cover only compute (not egress, scan, or throughput costs), or require you to already understand the pricing model well enough to fill them in — which is the exact problem beginners have. One complaint puts it plainly: 'data scanning costs are too high for beginner level users if not provisioned correctly.' The people who need this most are the ones least equipped to use what exists.

This is a business and not a feature because the buyer is making a four- to five-figure annual infrastructure commitment based on essentially a guess. Getting it wrong isn't just expensive — it's architecturally sticky. A tool that lets someone input their expected read/write patterns, data volume, and growth rate and returns honest monthly cost projections across database options saves the kind of mistake that costs a startup $30K in a year and requires a rewrite to fix. That's a real and recurring need as every new project, every new service, and every new hire who starts a side project encounters it fresh.

What to build

Build a web-based calculator where a developer inputs expected read/write throughput, data volume, growth rate, and query patterns, and gets a side-by-side 12-month cost projection across DynamoDB, MemoryDB, ElastiCache, and Timestream — including egress and scan costs that vendors hide in footnotes.

Where to start

Launch as a free tool targeting DynamoDB specifically because it has the most-feared pricing model and the most searches for 'DynamoDB cost calculator' — free traffic from engineers who are already in the research phase and already anxious, converting to a paid report or saved scenario export.

The hard part

The free utility version spreads awareness but doesn't obviously convert to revenue — you need to design a clear upgrade path (saved scenarios, team sharing, architecture review reports) before you've proven enough demand to know which of those premium features people actually want.

How it makes money

Free for single-scenario calculations; $9/month or a one-time $29 fee for saving scenarios, exporting PDF architecture cost reports, and running multi-environment comparisons (dev vs staging vs prod).