sodium hypochlorite

Hello. i am wondering if its safe to buy sodium hypochlorite from ebay from a reputable seller, instead of paying 30 pounds for a tiny amount from an MMS2 vendor?
im also wondering why a post i made about an emergency regarding an issue i have has not been posted.

I hope you meant calcium hypochlorite, not sodium hypochlorite (Clorox). Calcium hypochlorite is available at all pool supply stores. It is usually marketed as "pool shock".