Dragonite Dilemma
I have finally been blessed with a Dratini from a 10k egg and now have 150 Dratini candies (thanks Halloween Event). Now I'm caught in a bit of a dilemma over which Dratini/Dragonair I should take all the way. My options are the Dratini I hatched : 543 cp with 84 IV, Dragonair : 1142 cp 72 IV, and Dratini 624 64 IV (doubt I would evolve the 3rd one). Is the 12% of IV really worth the additonal amount of candy? I'm most likely going to fully power up the Dragonite regardless of moveset but the higher IV Dratini would require a lot more resources to max out. Currently level 28 trainer btw.
Answers
To add some numbers to that, I'm guestimating that your dragonair is about level 24 (use the IV calculator to confirm.
To get your hatched Dratini into a fully powered up Dragonite will cost 125 candy to evolve + 62 candy and 75,000 stardust to power up for a total of 187 candy and 75,000 Stardust.
To get your Dragonair (est 24) to a fully powered up Dragonite, will cost 100 candy to evolve + 40 candy and 51,000 Stardust to power up for a total of 140 candy and 51,000 Stardust.
The dilemma of course is that the 84 IV Dragonite will have a slightly higher CP than the 72 when fully powered up. Up to you if the extra 47 candy and 24,000 stardust is worth it, but I'd probably go with the Dragonair since you only have 150 candy.
It becomes incredibly expensive candy wise to keep up the rarer mons candy wise if they are hard to find in your area. Dratini are incredibly rare around me so it's very hard to keep my dragonite maxed.
If it wasn't for the Halloween event it would have fell behind quite a bit. I would go the cheap candy route if they are rare.
Why not all three? Just put on your running shoes and start training for marathons. ;-)
In the case of Dragonite/Snorlax/Lapras, I personally think the best approach is to power up whichever mon will require the least amount of candy, since these candies are super hard to get in the wild (and agonizingly slow to get via the buddy system). I don't think you'll notice a performance difference between an 80% IV Dragonite and a 70% IV Dragonite anyway. Heck, I have a 60% IV Dragonite - my highest CP mon - and he's super useful for both attacking and holding a gym slot.