"Use USPS Flat Box
shipping. You can ship as much as 75 lbs for around $15."
Good for lead, not so good for
books. The flat rate boxes are all fixed size, and you'll neer fit 50# of
books into any of them. I don't think $15 will buy you the large box, either. IIRC they start at ten bucks or so now, for something much smaller than a shoebox.