This is done to guarantee that the position is closed. Don’t panic! The coin is not really sold at this price; the actual price is determined by the market at the time the transaction is made. For example, the service places an order to sell 1 BCC at 0.00050000 at which time the buy book (Bid orders) is:
4 BCC at 0.18 btc;
5 BCC at 0.179 btc;
2 BCC at 0.175 btc.
Thus, your 1 BCC will be sold:
4 BCC at 0.18 btc;
5 BCC at 0.179 btc;
1 BCC at 0.175 btc.