At level 30 a 100IV gyrados is 2400, a 98IV gyrados is 2366. For me.
Pokemon order of importance goes:
Pokemon Type
Move Set
IV
CP
You won't know the move set til after you evolve it.
I'm doing CP until lvl 40. When I'm there I'll just snipe 100IV's for the big ones (gyarados, charizard, dragonite etc.) and keep the rest normal. Never going to use most of them anyway