Kitebuilder.com

[Stan]

Bamboo skewers from the grocery store sometimes have some nice pieces in the bag, and cost very little.
I bought about 50 pairs of bamboo chopsticks at an Asian market for $3 and have used them for spars, stirring paint and pinning carpentry joints.
NAFKA's Bruce Lambert sells some wonderful node-free bamboo spines for fighter kites. They are probably the easiest stuff to work for tiny kites and are very cheap.
Garden centers sell bamboo up to around 2" for around $4 a pole, but it's not always the best variety for kitework, and sometimes stored poorly.

A shop here, Solei Bamboo, sells it up to 10 inch diameters in 20 foot lengths, but anything over 3 inches is too big for kite spars and requires a heavy froe and mallet to split. The larger diameters are harder to split, but the outer skin is much stiffer.

How I do go on!