I know what you're talking about with getting burned out. I had a collection that did that to me once, but it involved a lot of animals that ate large and large amounts of food, like bearded dragons and horned frogs.
I would like to make breeding animals at least a part time job for me, because I simply love the animals, and if I can make money at it I'd like to.
I don't see darts and mantellas wearing me out to the point that ther other animals did simply because I don't have to clean their tanks every day. Bearded Dragons are the messiest lizards I've ever seen or owned, I now have Leopard Geckos I'm breeding, and they require very little maintenance, and are very fun to watch.
With the animals now I'm rather limited on space so I won't be able to attain a collection too large for me that will burn me out.