These are in good condition and circa 1977.

Thanks guys .
Pat

However, what is being offered here is the 1st edition Traveller rules (books 1-3), not the revised edition LBB's.  The reprints from Far Future Enterprises used the revised ruleset, so that really doesn't have that much of a bearing.  I would say about $15 at most, based upon what I have seen on ebay.  This also assumes that the box is present.  If it's just the rules, then cut that in half, which fits in with Badmike's assessment.

Mercenary (Book 4) is easily the dog of this set.  It was the most reprinted of the LBB's, with 23 printings under its belt.  High Guard (Book 5) wasn't far behind in that arena, but High Guard is more valuable due to being far more useful.  There is also one other thing that makes High Guard different.

What is at question is the copy of High Guard.  Is it the first edition, with the faulty starship design sequence, or is it the revised edition?  (Look on the copyright page.  It will tell you.)  If it's the 1st edition, you might get extra on that one, because those are a bit scarce compared to the revised edition.