Rear OX came in the XJ44 when I bought it, I bought the front when I built my front 44 last summer from 4wd hardware. It is listed for $840 currently, not including cable, but I got a $100 gift certificate when I ordered. (I also don't remember it being that expensive, but I can't remember)
I only have a few runs on them, but have nothing bad to stay. Diff cover took a beating, and the only thing that happened was it rounded off the socket head set screw that is the drain plug. (A dremel will fix that when I get around to it)
Despite what some people will say, adjusting the cable is not hard. Adjust it so it works while tires are jacked up, then use loctite like the directions say, and you won't have to adjust it again.