Evolve Before You Sell

The Collector pays for two things: the species, and then the individual pocket monster. The species half is decided by its total base stats — and it does not rise smoothly. It moves in four brackets, and crossing one multiplies what you are paid.

Under 330 total base stats, a pocket monster is worth its stats once over. From 330 it is worth twice as much, from 460 five times, and from 540 fifteen times. An evolution almost always pushes a species across at least one of those lines, which is why an evolved pocket monster sells for so much more than the one you caught.

Magikarp is the clearest case. Unevolved it sells for around 200 Gold. As Gyarados it sells for around 8,100 — forty times more, from the same catch, because Gyarados clears every bracket. Growlithe goes from about 700 Gold to about 8,325 as Arcanine.

Nothing you were keeping it for is lost on the way. Quality, IVs, nature and the Original Trainer all carry over unchanged, and the pocket monster is fully healed into its new form. So if you are about to sell something you could evolve first, evolve it first.

Some are already high enough the moment you catch them, because the zone they live in spawns them past their evolution level. Vulpix on Rota 8 is caught at level 25-32 and evolves at 20, so it is ready straight away once you have a Fire Stone. Doduo on Rota 12 (Silence Bridge) is caught at 28-38 and evolves at 31, so most of the ones you catch can evolve on the spot.

Others in the same position: Drowzee on Rota 8, caught at 25-32 and evolving at 26. Seel on Rota Marítima 19, caught at 35-45 and evolving at 34. Slowpoke in the same zone, evolving at 37. Koffing and Grimer on Rota 17 (Cycling Road), caught at 35-45 and evolving at 35 and 38. Magnemite and Voltorb at the Power Plant, caught at 45-55 and both evolving at 30. Dragonair in Dragon's Den, caught at 55-65 and evolving at 55.

And some are short of it, which is where you have to do the arithmetic. Magikarp is caught at 12-19 in Cerulean Cape and evolves at 20 — one level of farming for the largest single jump in the game, on the worst learner in the game. Growlithe asks for far more: it lives on Rota 3 and is caught at 8-15, while Arcanine needs level 20, and Growlithe is a slow learner. Only the pocket monster you are actively hunting with earns experience, so that is a real stretch of farming for each one — count it against the Fire Stone before you buy.

Evolutions that need a stone cost you the stone as well, so weigh that against the gain before you buy one.