Great idea! And also if one of your other kids is old enough you can instruct them how to make some (blocks, at least) out of yarn and plastic canvas. I googled plastic canvass balls, but those are pricey. Might have to stick with home-made canvass ten-base blocks instead of large plastic canvass "beads". I remember using plastic canvass to make barbie doll furniture following a pattern when I was nine. Good times.

Youth lives by personality, age lives by calculation. -- Aristotle on a calendar