Dave,
I like the grades and crossover. I don't know how much more involved it will be building it; if you want to spend the extra effort since you will be building the other layout sooner or later. Do you still plan to leave this layout up after you get the other going to where you can run trains? If so then maybe it is worth the effort.
Im thinking ripping plywood or OSB mY be better cost savings and do as well.