My game balanced out around level 21, and I now get equal amounts of boards, nails, and expansion permits. I also still get seeds shovels and hammers in enough quantity for upgrades.
Current stock: 10 boards, 10 nails, 12 permits, 9 seeds, 8 hammers, and 2 shovels. My toolbox max capacity is at 60. I have 5 slots in my herb garden, next upgrade at 28.