Additional useful reading (Google it) :
"Growing euphorbias successfully - getting more of them : Sowing" by Rikus van Veldhuisen.
Take note that the plant's sap is known to be somewhat toxic, so don't forget to wear gloves when taking care of it.
Shipping is 2$ to Canada and 3.50$ to the US. If you buy more than one lot, I'll combine shipment at no extra shipping cost.