Yea, epistane has a distinct taste/smell. And it is banned now. There's plenty of reason to fake it and sell it on ebay. filling 100 caps with baking soda is gonna cost a couple dollars, and you can probably sell it on ebay for 50 bucks. That's quite the incentive. Especially since the buyer has no recourse if he's sold a bunk product, as he was trying to buy something illegal anyway.
Havoc actually went off the market years ago, there are just still bottles floating around. It's never been reformulated.
Most manufacturers of prohormones have simply ceased to produce/sell their products, rather than reformulate to try to get around the new law. This recent ban is far stricter than previous ones, and has broader implications. Penalties are also severe enough that nobody's really taking the risk.