Skip to content
allanninal.dev/build
Collaborate

Part 6 of 7 · Quote comparer series ~5 min read

What the quote comparer costs

Quotes are low volume and each one is a multi-page document, so the read is the whole bill. Sixty quotes a month is a busy small builder or a procurement function at a twenty-person company. Here is where each cent goes.

Key takeaways

  • About $133 a month at 60 quotes. Roughly $552 at 250 quotes.
  • One Bedrock read per quote is the only line that scales. Everything else is rounding.
  • Nothing is always-on, so a quiet month genuinely costs almost nothing.
  • Document reads dominate completely. Everything else is under a dollar at every volume.
  • The duplicate test runs before the read, so resends are free.
  • The three real risks: a retry loop, storage nobody expires, and a bigger model than the job needs.

The bill at three volumes

These are US East prices at the time of writing, at three volumes that bracket most small businesses. Find the bar closest to your own and read across.

Monthly cost of the quote comparer at three volumesA stacked bar chart with three bars, one per volume tier: 20 quotes totalling about $45, 60 quotes totalling about $133, and 250 quotes totalling about $552. Each bar is stacked from bands. The largest and fastest-growing is Bedrock, one read per quote, in teal. Then SES for the messages, in pink. Then S3 and DynamoDB storage in green. Then a fixed orange band for Secrets Manager and AWS Budgets, which is eighty-six cents at every volume. Then a grey band for Lambda, SQS and CloudWatch. A note says the read is the only bar that grows with the business and the orange band never moves.$0$200$400$600$800~$45.2720 quotes~$133.3360 quotes~$551.61250 quotesBedrock — one read per quoteSES — asks, results, receiptsS3 + DynamoDBFixed — Secrets Manager, BudgetsLambda, SQS, CloudWatchThe read is the only bar that grows with the business. The orange fixed band never moves.
Fig 1. The monthly bill at three volumes. The teal band — one model read per quote — is the only part that grows; the orange fixed band is the same 86 cents at every volume.

Line by line

LineAt 60 quotesHow it scales
Bedrock read$132.00Linear. One call per quote, roughly 1,800 in and 200 out tokens.
SES$0.03Linear. About 0 messages per quote.
DynamoDB + S3$0.29Storage grows with what you retain, not with throughput.
Lambda + SQS$0.12Linear, and effectively free at this scale.
CloudWatch$0.16Flat, if you set retention. Unbounded if you do not.
Secrets Manager$0.40Flat. One secret, $0.40 a month.
AWS Budgets$0.46Flat. Two actions, so you find out before the bill does.

There is no messaging line: the comparison is a page, not an email. The read band assumes a multi-page document and the terms pages, which is where the tokens go.

The three ways this bill surprises you

Every one of these has happened to somebody, and all three are cheap to prevent.

  • Re-reading a document on every comparison. The extraction is cached against the document hash. Without that, one quote compared four times costs four reads.
  • OCR on documents that have a text layer. Checking first is one line and removes most of the OCR bill.
  • Storing originals in Standard forever. Quotes are read once and then rarely. A lifecycle rule to Infrequent Access after ninety days is worth setting on day one.

What it costs when nothing happens

This matters more than the headline number for a seasonal business. In a month with nothing to process the bill is the fixed band: Secrets Manager at forty cents, AWS Budgets at forty-six, and a few cents of storage. Call it a dollar. There is no instance to stop and nothing to remember to turn off.

The monthly bill at four volumes plus one failure modeA horizontal row of five boxes. Quiet month, about one dollar. 20 quotes, about $45. 60 quotes, about $133. 250 quotes, about $552. And one bad retry loop, about two hundred dollars. A note says four of these are the design working and the fifth is a missing dead-letter queue.THE BILL, AT A GLANCEQuiet month~$120 quotes~$4560 quotes~$133250 quotes~$552One bad loop~$200Four of these are the design working. The fifth is a missing dead-letter queue.
Fig 2. The bill at a glance, including the one that is not a volume at all. A retry loop with no dead-letter queue costs more than every legitimate use of the system put together.
  • Management
  • Analytics
  • Front-end & mobile

Set these on day one

  • A dead-letter queue on every SQS queue, with a maximum receive count of three.
  • Thirty-day retention on every CloudWatch log group. There is no default that is safe.
  • An S3 lifecycle rule on the object prefix, tiering at 90 days and expiring at your actual record-keeping horizon.
  • Two AWS Budgets actions — one that emails at half your expected spend, one at double it. The second is how you find out about a loop in an hour instead of a month.
  • Provisioned concurrency: none. Nothing here is latency-sensitive enough to justify paying for a warm function.

Next: the same system drawn for engineers — service names, resource identifiers, IAM scopes, table schemas and the model id.

All posts