Steve-
Unless the seller is a little old lady who absolutely has no clue what they have, I generally ask that the owner price their own goods. Too often I find that sellers who seek "Best Offer" are either simply looking for strokes, or they take my offer and shop it around. Said another way, my experience is that sellers who seek the "Best Offer" are not serious about selling yet.
John Barron
Minneapolis
http://www.velostuf.com