so we know each Pokemon as a level and an IV(Indivudual Value) which determine CP. You can learn more here : https://pokeassistant.com/main/ivcalculator
What I was wondering is, at what point should we consider powering up a lvl 20 Pokemon (from an egg the max lvl is 20) to 30 (which is the max lvl for wild Pokemons). The rarity, IV % and moves are certainly some factors.
For example is it worth powering up a Dratini with 95% IV perfection from lvl 20 to 30 ? Or should you look for a wild lvl 30 with less IV % ?
I'm not especially looking for a concrete answer, except if there is a tool somewhere, but rather for answer pieces.