A game does not have a price. It has twenty of them, and they are not conversions of each other.
Most people assume regional prices are the dollar price run through an exchange rate. They are not. Publishers set each region independently, against local purchasing power and local tax — which is why the gap between the cheapest and dearest country is routinely larger than any seasonal sale.
Why nobody else publishes this
Storefronts show you your own price. They have no reason to show you anyone else's, and no competitor collects it because it means reading the same product page once per country, every day.
We do exactly that, for every game we track, across 20 regions. The live index is here and updates daily.
What the pattern looks like
Broadly, prices track local purchasing power: Turkey, Argentina, India, Brazil, Pakistan and Indonesia sit well below the US and Western Europe, while Japan, Australia and the Nordics sit above.
The pattern is not clean, though, and that is the interesting part. Publishers set these individually, so some price a title aggressively in one market and barely discount it in a neighbouring one. Two countries with similar economies can differ by half.
What this does not mean
It does not mean you should switch regions. Changing your Steam store country with a VPN breaks the Steam Subscriber Agreement, and Valve enforces it. A locked account takes the whole library with it.
What it is genuinely useful for: knowing whether the price you were quoted is normal for where you live, and understanding why a friend abroad paid something completely different for the same game.