That amp has disappeared and popped up on the GC used site about 6 times in the last few months. My guess, is that someone bought it and it got damaged in shipping so it was returned. Then, rinse and repeat. They keep listing it. It keeps selling, only to be returned again when the buyer discovers something is wrong with it. Over and over. It's finally got to a point where GC had to acknowledge the damage and "discount" it hoping some sucker will come along and buy it.
Same thing happened with a Roadster Combo I bought from GC about 4 months ago. Sold as excellent condition, but arrived to me damaged and missing the footswitch that probably fell out of the gaping hole in the side of the box. I returned it, and it popped back up on my local GC's used page for sale. Again, listed in excellent condition with footswitch. Then it disappeared, and popped back up in Colorado Springs, Co. for sale. Yup, you guessed it.. in excellent condition with footswitch. That was when I called them out on it, and then it disappeared for a couple of days and when it came back up again for sale in Colorado Springs it was listed in "fair" condition and was discounted a little. Seems to be their SOP, they keep throwing it against the wall to see if it'll stick.