That sucks about Keebler. I wanted that Moria set! I might just have to make my own castings, then.
As 3D printers are becoming cheaper, you will see more and more companies offering... plans?... available to download. I'm hoping these will revolutionize the wargaming and model train hobbies. Patience and time will tell. Still, I think I'm addicted to the smell of plaster of paris, and I love my "adult Legos".
I would certainly start with the moulds that don't have fine lines or little pieces. Mapper and I have a recommended list floating around the boards somewhere. I use PoP and mix it to runny pancake batter consistency. (Being from cowboy country, I know my pancakes!
) Anyway, I hate lightweight Hydrocal. It is light, but it makes lousy, ill-defined casts. If you live in the Great White North or anywhere cold or soggy, a fruit dehydrator will speed things along, or put them on the oven's lowest setting with the door open an inch or two. If you cast every day, at the end of the week, you will have enough to make a good start of your project.
I am more than happy to trade blocks or cast models for miniatures, if that's your thing.