Having just moved a couple months ago I was a box expert! I bought them at Lowes, and Home Depot for less than $1 each. But found the large ones too big to carry comfortably but a few were handy for blankets and quilts. If you really want free boxes go to the stores early and look around for shelf stocking near toilet paper, paper towels and see if they will give away some of the large boxes those items come in. Stay away from places like Dollar store and Big Lots, as those big boxes are poorly made cardboard and fall apart, tear easily, and disintegrate when damp. and have a lot more chance of carrying cockroaches and other bugs. Medical supplies come in large boxes sometimes and a pharmacy might give them away. Also fast food restaurants get things like buns, chips, and other foods in large boxes. Go ask there too.