So Power up or Evolve first?

Neither. Collect stardust and candy as much as you can to lv up and catch higher cp mons first.

depends, do you see Ghastly frequently?

Release everything you find until level 35 when cp stops going up then use candies.

Wait until you have enough candies to fully evolve into Gengar. By that time, you'll have a decent candidate for evolution. Afterwards, dump candies into it and power it up until you run out of Stardust.

>>27239346
How many candies for Gengar from Haunter?

>>27239224
What level does cp stop going up?
>>27239297
Serebii only lists up to level 30 so this guy either made a typo or doesn't know shit

>>27239502

Probably 100.

>>27239502
100

>>27239627
>What level does cp stop going up?
Never, but the time it takes to level gets exponentially higher. If you see gyms with lower than 1000 cp pokemon, you should be fine after lvl 15 to start investing. Otherwise, keep going until 20.

>>27239179
Doesn't matter, power up is % based. Power up Gastly 2 times, then evolve will result in the same level as evolve first, then power up Haunter 2 times