I based it on the price I used to pay 50$. And why can't 11$ be a price mistake? I have no patience to sit arguing so what ever your reply will be you will win...
The definition of price "mistake" is when someone makes a mistake and not that something is cheap... Here it's obviously not a mistake, 5 people can't do the same mistake.
And again these are sellers with no feedback!
So you gotta be dumb to buy from him even if it's free