User blog comment:BonesMcGee/Brainstorm: Potential savings in using the hurry hatch trick/@comment-5309185-20120803144005

Well, you forgot that while raising dinos up to level 4 they still earn some coins for you.

But, as it was already said, the time is essential. Doing the hatching hurry cost trick you can save a bit of time (still have to deal with a great amount of patience since sometimes you have to do more than 100 attempts to have a success).