Sign up for a free account at the Walmart on-line Photo Center here, and you'll get a special code for 25 free 1-hour 4x6 photo prints to use on-line in your welcome email.
Plus, right now you can print a coupon for a free 5x7 print of your favorite back-to-school photo. Thru the end of September. Look for this graphic here.
Also, since it's back-to-school time, I like to check out the Walmart Clearance Apparel section here. For school clothes for my ever-growing boys. (I've sorted it with least expensive items first.) You can make pretty nice outfits for $10-$15 total (top and bottom) if you hunt.