OK, for some reason that posted without me typing!!
Anyway....I like this answer....I love my maternity photos...those would be hard to give up. I did all of the pics with my DD though, maternity, newborn, 3, 6, 9 and 12 month. I like the idea of just going somewhere else cheaper for the other ones or if you have a friend with a nice camera...you could just do that for the gaps :) I would do something though for the 3 & 9 month though b/c they really do change so much