LNL.org's?

[Plutonic]

Are they valuable?

[dnk]

Specific combinations are, but most are less than reg fee

[dman_2007]

Price depends on the combination like dnk said, random combination are selling for reg fee. see here (http://3character.com)

[htmlindex]

Depends, if it's h2o.org, yes, but most of them are worth reg fee max with plenty dropping or available for registering.