Ah, the never ending debate on the ethics of the old "reject and reprice" move.
I will say this. Currently, *many* cards on the site are mis-priced (in both directions). Everything was priced based on Beckett book value. Beckett value is now irrelevant as almost nobody can see it. Slowly, we will see prices move toward the past sale number instead.
So, if you happen to see a card priced way below the past sale number, it might be a good idea to just grab it instead of trying an offer.