my bread and butter arrow shafts are poplar dowels from Menards, i have to sort through about 200 shafts and i'll walk away with maybe 20 useable ones, but its worth it at 18 cents a piece.
They are durable, easy to work with, take stains well, and stay pretty straight.
The stiffest 5/16" will give about a 45lb spine, great if i can get enough, but usually i get 3/8" and plane them down to my desired spine. its not uncommon to find nearly perfect poplar dowels, none or maybe 1 grain run-off in a 36" length.