I have bought the $100 Purple Heart and it was kindling in minutes; never again.
Dang, what were you training against? I have a purple heart (1-1/8 inch diameter) and it was withstood the test of time against oak, ipe, hickory, other purple heart, and even the maple tree in my front yard.
Perhaps most accurate to say he took my money and he said, "this is Purple Heart." I found it very light in my hands and it just seemed to have no flex. I did nothing crazy with it, just basic paired practice.
For the wood workers, my jo that lasted the longest but has inferior wood has a bigger diameter than standard and that feels nice in my hands. Shorter also seems more durable.
Cold Steel was making a polymer jo - has anyone tried those?