The X1 is cheaper at Manafont:
http://www.manafont.com/product_info.php/ultrafire-x1-q5-3mode-memory-led-flashlight-118650-p-4048
But that host isn't that well made. I've had problems with the switch and the threads aren't that great. My review:
I wound up using the light as a host for a neutral XP-G. It works, but the switch is annoying. And the XR-E reflector isn't great for the XP-G.
I ordered this AA/14500 kit and may put a Nichia 219 LED in it (also have a Ultrafire C3 stainless on the way; honestly I'd rather put the Nichia in my Sunwayman V10).