Why This Page Exists
This site publishes cost tables, and a cost table is only useful if you can see where each number came from and how old it is. The sourcing rules are written down here so they can be held against the figures.
This page covers one thing only: where the money figures come from and how much you should trust each one. The rules for which sources are acceptable and how an assessment is labelled — scoring, fit, what gets recommended — are on the Sources & Methodology page.
The short version: every figure in a cost table should trace to a primary source — the vendor’s own pricing page — with the date it was read. Where that is not possible, the figure should be labelled an estimate or an assumption, or left out.
1. Where a Price Comes From
There is exactly one acceptable primary source for a price: the vendor’s own pricing page.
| Order | Source | How it is used |
|---|---|---|
| Primary | The vendor’s own pricing / billing page | This is the number that goes in the table. Nothing overrides it. |
| Cross-reference | A second source that is not the vendor (a reseller, an official help-centre article, a rate sheet PDF) | Used only to catch a reading error. Must be labelled as a cross-reference, never published as the price on its own. |
| Not a source | Search-result snippets, AI-generated summaries, cached price trackers, affiliate roundups, YouTube reviews | Never used to establish a figure. At most a lead that sends me to the primary page. |
Two consequences worth stating plainly:
- A vendor’s own help centre counts as the vendor. When OpenAI’s pricing page will not load but its help centre states the plan price and the billing terms, that is a primary source and it gets cited as one.
- When two vendor pages disagree, the vendor is wrong, not the method. I cite the page that governs billing and note the conflict rather than silently picking the nicer number.
2. What Every Cost Table Must Carry
A dollar figure on its own is not verifiable. Cost tables should identify their sources and assumptions, which is why every table carries four fields — and a row missing any of them should not ship:
| Field | Why it is mandatory | What it looks like |
|---|---|---|
| Price | The number itself | $59 |
| Billing cycle | The rate is often only real under annual billing | per seat, billed yearly |
| Read date | A price is a fact with an expiry date | 2026-09-15 |
| Source | Where it was read, so you can re-check | jasper.ai/pricing |
Two more attributes should travel with every table even when they are not their own column:
- Currency — stated explicitly. USD anywhere a regional price is not the vendor’s own.
- Region — stated when a vendor prices by country, because a US list price is not a global price.
The worked example is the pricing table on Best AI Writing Tools — four tools, one row each, all four fields populated.
3. Three Confidence Labels, and How You Can See Them
Not every number on a cost page has the same standing. Rather than blur them together, I label them, and the label is visible in the table:
| Label | Meaning | Visible marker |
|---|---|---|
| Verified | Read from the vendor’s own page on the date shown, with the URL attached | verified · 2026-09-15 · <source URL> |
| Estimated | Calculated by me from verified inputs, using a stated formula | estimated · <formula or basis> |
| Assumed | A working assumption with no vendor confirmation — a usage pattern, a seat count, a scenario | assumed · <basis> |
A figure with no label should not be published. If a number cannot be assigned to one of these three buckets, it should be cut from the table rather than softened in the prose. “Around $60” is not a label.
Estimates and assumptions can carry a whole verdict — a TCO projection is mostly estimated and assumed by nature. That is fine. What is not fine is presenting one as a vendor list price.
4. How Often Prices Are Re-Checked
- Target cadence: every quarter, cost tables should be re-read against the vendor’s live page and their read dates refreshed.
- Event-driven pass: when a vendor publishes a price change, the affected rows should be re-read and corrected within 7 days of the change becoming public.
- On report: if a reader emails a correction, that figure should be re-checked ahead of either schedule.
The read date in each table is the record. Source dates indicate when information was checked; prices and terms may change afterward. A table whose newest read date is three months old is a table that is three months old, and it says so.
5. What Happens When a Number Is Wrong
- Re-read the primary source. A correction starts by going back to the vendor page, not by patching the number from memory.
- Fix the figure and its read date. Both move together. A new number with an old date is a worse defect than the original error.
- Log it in the Editorial Changelog. The correction should be dated and described, so the record shows what changed rather than quietly looking correct.
- Say so on the page when the error affected a verdict, a ranking, or a total.
Silent edits are the thing this section exists to prevent. If a price was wrong on Tuesday and right on Thursday, the changelog says so.
6. Affiliate Relationships Do Not Change a Number
Some links on this site are affiliate links. No price in a cost table is affected by that. The rules are the same for a vendor that pays a commission and one that does not:
- The number in the table is the vendor’s own price, read from the vendor’s own page.
- A renewal trap, a hidden overage, or a punitive exit cost is written down whether or not the vendor pays anything.
- No platform can pay to be ranked higher, removed from a limitation, or given a friendlier billing note.
The full statement — what an affiliate link is, how it is labelled, and what is refused — is on the Affiliate Disclosure page.
7. What I Do Not Do
- No tax, legal, or financial advice. Cost tables describe what a vendor charges. They are not advice to buy, and they are not a substitute for your accountant.
- No vendor copy approval. Vendors do not get to review, edit, or approve a page before it is published. A correction is made because a figure was wrong, not because a vendor disliked the tone.
- No paid placements, no sponsored ranking, no “as seen in” slots.
- No invented experience. If I have not tested something hands-on, I do not write “I tested it”. Analysis of public data is labelled as analysis of public data.
- No unlabelled numbers. Covered in section 3, and it is the rule the other six depend on.
8. How Articles Are Written
- AI tools are used in drafting and language editing.
- AI-generated output is not evidence of a product’s features, price, or performance. Evidence is a vendor page, a published rate sheet, or a recorded observation.
Questions or a Correction
If you want the source behind a specific number, or you think one is wrong, email [email protected] or use the Contact page. Corrections are welcome, and one that changes a figure is logged with a date.
