How these prices are gathered

Every number on this site is an observation: one price, from one provider, on one date, from a named source. It is never an estimate, and it is never an average of things that were not measured.

Every price carries its date

A price with no date is a rumour. Vietnamese prices move, so each observation records when it was seen and how precisely that is known: a day, a month, or only a year.

Prices are then sorted into three bands:

• Fresh, seen less than 6 months ago.
• Aging, seen 6 to 18 months ago. Still shown, still usable, treated with more care.
• Stale, seen more than 18 months ago. Shown, greyed out, and left out of the calculator total.

Nothing is ever deleted. A new observation is added next to the old one, so a price has a history you can read.

Where a price came from

Each observation is tagged with how it was obtained:

• Paid in person. Somebody paid this and kept the receipt.
• Quoted by the seller. The provider gave this figure directly.
• Published price list. Taken from the provider's own tariff, website or price board.
• Sent in by a reader. Submitted, checked, and labelled as such.

A tier is not a quality score. A published price list can be more reliable than a single receipt. It tells you what kind of claim the number is, so you can judge it yourself.

Prices that rest on a single source, or that come from a different city and are shown for comparison, are marked as such next to the number.

Both currencies, and the rate

Prices are recorded in Vietnamese dong, because that is what the provider charges. The euro figure beside it is a conversion, stored with the rate and the date it was converted at, so it can be recomputed rather than quietly rotting as the rate moves.

How providers are ranked

The order of providers on a category page is computed from the data alone, in this order:

• Whether its prices have gone stale.
• How often it holds the cheapest current price.
• How many of its services have a price at all.
• How recently it was checked.
• How complete its listing is: a website, a phone number, opening hours.

Paid placement

Some providers may pay to appear on this site. When they do:

• Paid placement is a fixed slot outside the ranked list. It never takes a position inside it.
• Sponsorship is not an input to the ranking. The ranking code cannot read it.
• A sponsor's own price claim is a vendor quote like anybody else's, with no privileged status.
• Sponsors are listed publicly.

A directory that tells you to stay home when staying home is cheaper is worth more than one that does not. That is the entire reason the rule is structural rather than a promise.

What is not here

This site does not give medical, dental or legal advice. It records what things cost and where. Whether a treatment is right for you is between you and a clinician.

Some categories are still thin. A category page with too few dated prices is kept out of search results until it is worth landing on, rather than published as filler.