Following up on Kleenexz's analysis, I recorded the results of transferring 574 legendary Pokémon. I divided them by level into 15, 20 or 25. Here are the results:
Level 25 Average XL candy per transfer = 3
Level 20 Average XL candy per transfer = 2.2
Level 15 Average XL candy per transfer = 0.625
Totals per level:
Level 25 – 108 Pokémon transferred, 324 XL Candy
Level 20 – 458 Pokémon transferred, 1010 XL Candy
Level 15 – 8 Pokémon transferred, 5 XL Candy
Here is the breakdown by Pokémon:
https://docs.google.com/spreadsheets/d/1unr6WevCqjWmPaTUuqvgl7qUjiCTyeUqIn5GDf3fiQ8/edit?usp=drivesdk
Please note this is with the paid pass.
by Other-Chemical