Rowan

Likely durability and portability. Think of it as something they use month over month and just mark the day with something like a string band. Bone would be light enough to keep with you, strong enough to not break, and common enough to be available for household use.

My exact thoughts. Give me this choice at 19 or 20, sure I'll restart. Now though, the money would just be nice to provide security to the most valuable thing - my girls.