I know several sellers from Australia, Sri Lanka, Indonesia, Thai and the Caribbean and They are all good. And Yes, they are all from ebay.
When you are going to buy something from "unknown seller", always try to ask him/her a tricky question like about the seed viability or do you ship your seeds with coconut coir (moist medium) or not.
From his/her response you will know if the seller knows what he/she is doing.