There aren't any. The last ones were registered earlier this year. In the last internet boom these often sold for $500. When the bubble burst they fell all the way back to reg fee. With sales rising again this boat has been lifted with all others though still a long way from the previous highs. Wholesale on these would be around $20-$30, end user low three figures. Have sold several to end users in that range myself this year. Last year I was selling them for DNF$!
I stand corrected... there are no LLN combos available, but I did find some NLL and LNL combos just now - I suppose there could be a case made that there is some difference, but it doesn't seem that lucrative to me either way.
1 - 0rn.com (DELETED on 08-28-03)
2 - 2wn.com (DELETED on 10-11-02)
3 - 4mv.com (DELETED on 06-11-03)
4 - 5ea.com (DELETED on 07-07-03)
5 - 62n.com (DELETED on 01-08-04)
6 - 78b.com (DELETED on 10-10-02)
7 - 7ea.com (DELETED on 07-07-03)
8 - 7pq.com (DELETED on 12-17-02)
9 - a0c.com (DELETED on 06-14-03)
10 - g8v.com (DELETED on 01-03-03)
11 - m4o.com (DELETED on 07-03-03)
12 - m4q.com (DELETED on 07-03-03)
13 - q4o.com (DELETED on 07-07-03)
14 - q4v.com (DELETED on 07-01-03)
15 - q4w.com (DELETED on 07-07-03)
Not that lucrative at this point for sure, though we have reported several four-figure sales of LLN domains at DNJournal this year. There is a big difference between the 3 classes. LLN are easier to sell because that convention is used by thousands of companies when naming products. NNL or NLL are occasionally used that way but far less frequently than LLN (even so, the examples you gave of those above are NOT available for registration - I just checked them. Though not as strong a class most of those also get registered at soon as they drop). LNL or NLN are rarely used and I completely avoid them. Doing a few searches on Google will confirm the usage patterns mentioned. As in all other categories, it pays to stay on top of what the market is doing today - what was happening six months ago is meaningless.