^ I agree with not rushing to evo 5-stars first. The most immediate boost evolving gives is doubling the the affection bonus. 4-stars and 5-stars have the same affection bonus stats gains (compared to 3-stars which have lower average gains from affection), so early on it's probably best to focus on evolving 4-stars rather than 5-stars for more cost effectiveness, until your team is a little more established. Also consider that 5-stars need 3 large dragons, which can be a ton of stamina to get if you're unlucky.