Let me put it this way. If your finances are such that you are worried about scrounging up $100 here and $150 there, you should probably be using what you have and not thinking about buying new gear that you do not need and cannot afford -- completely aside from the fact that you have a baby on the way. You are not only going to have the expenses associated with the baby, but you are also not going to be able to work full time for a while if you're like most of my friends who've had kids. Altogether, things get very costly very fast.
I have been on a limited income for a long time (try being a grad student, and then a researcher in a very expensive city, and see how much money you can put away) and I've made my share of stupid spending mistakes and I regret nearly all of them. There is no gear that is worth putting yourself in big debt over. I would not have the cameras I have today if I hadn't inherited them or been able to use an equipment budget to buy them (in the case of the dSLR) -- there is no way I would even consider buying them, I cannot afford this kind of equipment. I may seem lucky in this respect, so what do I know, right? -- but there are plenty of other things that I want or think I need to fulfill one desire or hobby or another that I recognize I cannot afford even though I really really want them (I haven't been on a horse for over five years, for example, and I used to be very into dressage, but it's just too expensive). There comes a time when you have to recognize your financial limitations and make choices, and having a baby on the way seems like as good a time as any for that. I don't want to sound harsh, but you already have some pretty nice cameras. I think it would make more sense to use what you have and save money for your baby and your future.