Let me explain supply and demand to you.



As you can see, there is a rough supply of 100,000 banx right now listed for sale on banx.io itself.
If we exclude those overpriced, there still is a supply of 36,000 shares at/under 0.006BTC each.

However, do you see ANY buy order? Nope, wonder why?
Banx share trades/sales are currently still regulated (minimum sell price used to be 0.0076BTC, seems to be 0.0055BTC now).
No-one is ready to pay that price.

So what are the options if you cant list them for less, but for the current price no-one likes to buy them?
Go off-site and sell them there for less there.

Thats the reason, and the only one, why he sold them "that cheap".