No. This isn’t common because most entrepreneurs don’t consider fairness to buyers (by any definition) to be their primary pricing goal. Most price based on value delivered to the buyer (how much better is your app than the buyer’s alternative?), the seller’s costs, or a combination.
Pricing based on perceived fairness to buyers has some practical challenges for sellers, like that the seller’s expenses - particularly team compensation - are not adjusted based on buyers’ locations.
Also, the alternative choices (in economic terms, “substitute products”) are often different across markets - not just different available apps, but completely different ways to accomplish the same task or spend time. There’s no reason to think that buyers in two markets receive the same amount of value from your product.
(Of course, there’s an argument that pricing something differently in certain markets might lead to more total revenue from that market, but that’s that’s optimizing for total revenue, not fairness.)