I'm not sure I've ever come across that problem with the binding, but I would say it's just that, that it's not binding. The transmitter when it stops flashing and beeps confirms that it's sent the bind process command and everything, but it doesn't confirm that it's actually successfully bound in any way. I would say either you have a faulty controller that's not sending the signal, or you have a faulty receiver board in the quad. and unfortunately, unless you have another transmitter that is capable of binding with it there's not much you can do in order to see where the fault is.
The quad does have its flaws, as I have explained in the article I wrote... it's main one is that it doesn't like the wind at all. I have one of the new version X5C-1 boards ordered which people say works very well in that particular quad, and I'm going to change it for the original board in the X5SW as they are basically the same quad, and let's see what happens then, it might turn out to be a lot better for whizzing up and down!! But one thing you do say, $100, that's a bit steep what you paid for it!!