I scanned all llnn.com "chinese" domains a few days ago and all of them are registered. Haven't checked nnll but seems to be the same. Seems to be mainly a chinese trend as more than 80% of owners are chinese. I prefer LLNN over NNLL but this may be just my personal preference as I have no data to support it.
By the way, the definition of "chinese" in this case is very precise:
Letters: No A E I O U V
Numbers: No 4 and no 0 in first position (e.g. 10 is fine, 01 isn't)
I've started to see some price increase at expired domains sites, especially for repeating letters/numbers, round numbers (like 10, 20, etc) and letters or numbers combinations with special meanings (88, cn, dr, etc). Number 8 seems to be especially desirable.
If we judge by the chinese involvement in the segment, I think there is a pretty good chance of a significant price increase in the near future, and prices are still pretty affordable, so it looks like a good opportunity, i you can buy them cheap.