Evolve 100% or 84% Magikarp?
The one with 100% IV has 142 CP and the one with 84% has 183 CP.
In order to make my 100% magikarp get the same CP as, I need to spend around 50k stardust and 50 candies. Is it worth it?
Answers
My point of view about magikarp evolution: do not bother too much about IVs and do not spend stardust powering up. Just evolve the higher CP one if it is close enough to the max CP bar.
Gyarados is no more a top tier attacker (without dragon breath) and defender, just evolve a ready-to-play one and do not power it up any further. It isn't worth the stardust...
Wrong. Everyone should care about the IVs. Although it is a long time from now, Gyarados will be getting its mega evolution down the line so evolving a Magikarp with good IVs will save you time having to gather candies again (even though you might be anyway from now til then). 400 candies is no laughing matter either. Even at a pier where they spawn like crazy, it would still take couple of hours. Make the most of them.