SN, the X-Kings have been a good tire although even those have gone up in price. I was able to get Pricepoint to do a price match for me on the 29x2.4 Black Chili compound tires for $48.45 each, the best price I could find with free shipping and no tax.
Like I said, the Maxxis Ikon 3C EXO TR 29" tire was also on the short list, Pricepoint did a price match on those for me as well, but at $61.79 which is a good price for those tires, just more than I wanted to spend. If you do get those however, please let me know what you think.
I'm actually replacing my worn out Racing Ralph FR/Conti X-King RR, which have been on my IP-036 (due to swapping wheels around). The Racing Ralph is a great tire if you want to replace it often, but at $80 retail, it's too expensive and too thin for me and my riding style. The Conti X-King on the rear has been pretty reliable, I don't think it was the Black Chili version so I am looking forward to how much different the new tires will be. The X-Kings have a high quality feel in the construction and the compound so we'll see if it becomes my new favorite.