"Buying in bulk can be a fantastic money move and a time-saving godsend," says Kristen Hagopian, author of "Brilliant Frugal Living."

Certain school supplies get burned through at a ridiculous rate over the course of the school year, says Hagopian. Depending on your child's age and class description, he will use lots of pens, pencils, paper, notebooks, printer paper, computer disks, markers and paints. While the additional outlay of cash now might not seem like back-to-school savings, you'll have cheaper supplies on hand for several months if you buy in quantity.

"No more rushed dashes to the store for another pack of paper. You'll save money on gas and you'll save the hassle," says Hagopian.

Buying in quantities at your local warehouse store and sharing the bounty plus the cost with friends also helps the budget. Pasta, meat, ready-made foods, desserts and produce can be found in large quantities at Costco and Sam's Club, and can easily be distributed to a group of friends who can share the cost of school lunches, Hagopian says.