I agree with above post.
However, get this, I raised all my prices yesterday to high book on some cards, and that stopped the low ball offers. Additional, I've sold 6 cards at HIGH book! Cards that I would have sold at low book if I hadn't been bugged by the low baller and upped my prices.
So thanks to the lowballers!
Still, I think allowing basic users (non $15/month) to have access to auto-decline offers would be a cool thing to have.