Oho! The people who sold me the bricks for the front yard? They have another 150 sq ft of the same stuff available. Which would be pretty sweet, considering the price, and also that it's very easy to compose curves etc without having to cut stones. I would need ~75 to 100 sq ft, I'm guessing, given I still have scraps left over from the last batch.
Trying not to interpret this as the universe telling me to jump into action on my side yard plans, because those are so newly hatched and unformed as to constitute a whim, and besides, as stated below, (another) major project just now? DO NOT NEED.
Still, I am powerfully tempted to snap the stuff up and let it sit until spring.