In summer 2018, Finland liberalized taxi pricing, meaning companies can now charge different rates. This extends to being able to offer flat fares in addition to the usual starting fee plus per-km plus waiting costs.
According to the Helsinki Airport site, there are now three companies operating taxi ranks at HEL, and:
Agency-specific price information is available in front of the terminals, on the information screens next to the taxi ranks.
However, I'd really prefer to figure out in advance which company to go with, instead of trying to compute flat fare vs variable rate across all three on the spot when jetlagged, tired and dragging along cranky kids.
How can I find out what is the cheapest option on any given day?
(And before you reach for that "shopping question!" close button, I'm not asking for the cheapest taxi today, I'm asking for the way to figure out the cheapest taxi.)