I'm usually for the business honouring pricing errors, but this is clearly a system error (or glitch). if it was 599$, for example, I could see this as a price error that should be honoured, but at 0$, it would be limit bad faith to request them to respect this price.
If those who jumped on this opportunity make them give thousands of dollars of stuff for free, you can expect them to respond with prices increases to recoup the loss, and that would have bigger repercussions on the CGN community than having 5-10 customers unhappy because they could not take advantage of a computer glitch, when they knew for sure it was an error, and not a deal!
Try to find another dealer that give such good deals and free shipping on top of this, and you will see there is not much of them out there, and I really want them to continu like this.
My 2 cents.
With that being said, I would really like to put my hand on a sig clone since I already have CZ's