Two things...I was advised to pre-order as they fulfill those as soon as a shipment comes in first. Also try the coupon code TY10 - it worked for me for 10% off that gets you to 260.
The Sentinel seems like a good, nicely priced sight. I decided against it because of how much it apparently obscures the iron sights on the Hellcat. I liked the 32 MOA circle around a 2 MOA dot, the more robust frame around a glass optic, and the side battery port so I don;t have to remove it. I don't like that I have to modify the index posts, but figure that without them I can mount virtually any sight if I want to ever change (which I seriously doubt I would).