Our approach
How we use sources
A useful source tells you what it describes, where it applies and when we read it. We keep those details beside every claim, store the document we read, and re-check the quoted passage before each release so you can confirm an answer yourself.
Documents first, then the claim
Every published fact starts with a document we can point to: a government or agency program page, a manufacturer specification or price publication, or an identified seller's own price. We record the document title, the section and the exact quoted passage, then write the claim from that record and nothing else.
How we capture and re-check a source
Our source reader follows each website's robots rules and crawl delay, fetches the page once, and stores the exact bytes with a SHA-256 hash. Two checks then confirm that the cited title, section and quoted passage still appear in the stored text. Each check result lives eight days; a build on an older check fails until the check runs again.
Keep price categories separate
An equipment price is not an installed price. A starting price is not a typical price. A manufacturer range is not a median. We show each price with its condition, configuration, place and seller as the source stated them, and we do not calculate a local premium without comparable observations and a stated sample.
Records expire on a schedule
Price, funding and tool records carry a thirty day review budget, installer records ninety days and product specifications one hundred eighty days. A record older than its budget stops the build until we re-read its source. A short emergency override exists for age alone, never for missing evidence, a changed quote or an expired rule.
An unknown stays an unknown
If a source does not answer the question, the page says the source does not specify it. We do not turn missing information into a zero price, an approval or a denial, and a table cell never holds an estimate in place of a sourced fact.
For general planning. Confirm program rules with the administering agency or your plan, and installation details with a qualified professional. This site does not determine benefits or medical suitability.