Not sure if this is done already or not, but based on the TPE blub it doesn't appear to be:
Is it possible to include the player's nationality in the TPE calculation?
Players from countries with more managers frequently sell higher than similar players from smaller countries due to increased bidding competition (impact on merch income, NT callups, etc).
Is it possible to adjust the TPE calculation to incorporate nationality as another filter, especially in cases where decent sample sizes exist?
Similarly, whether a player is an active member of the country's NT/U-21 team should also be taken into account imho.