But ClassyMommy blogger Colleen Padilla says you can cut those costs -- and still keep the kids happy.
Her first tip: Before you shop, look at what the kids already have.
"Go through the closet, see what fits, what works, what doesn't," she advises.
"A lot of the same clothes, kids are going to fit in. Also, can you re-purpose clothes? Can you add embellishments or add embroidery to a pair of jeans? What can you do to make things still work and the kids really excited about them?"
And if you do decide to let your kids pick some new, trendy items, look for them at a discount.
"Hello Kitty's hot this year," Padilla says. "Little girls want a Hello Kitty backpack. They want 'jeggings' -- jeans/leggings. They want the coolest clothes. You want to buy them at the cheapest price possible, so why not shop off-price?"
We found jeggings at T-J Maxx for $7.99, instead of the suggested retail price of $20. They also had a kids' Nike sweatsuit -- with a retail price of $44 for $17. The top can be used as a Fall jacket, making this an even better buy.
The store also had backpacks and lunchboxes for about half-price. In addition to saving money while shopping, Padilla had tips for Moms to save time and tension on those hectic back-to-school mornings.
She suggests making mornings less hectic by picking clothes, organizing backpacks and packing lunches the night before.
To save money on lunches, she suggests using cloth napkins instead of paper. You can pick them up cheap at thrift shops or make them from cloth remnants. And pack lunch in re-useable containers instead of repeatedly buying plastic bags.
"Those reuseable containers are genius, especially for fruit," Padilla says. "I love putting fruit in reuseable containers, it's not going to get crushed."
Padilla's other tips include putting children to bed 10 to 15 minutes earlier each night for a week or two before school starts, to help children adjust to an earlier bedtime, after they've been up later playing during the summer.
For more of her tips, you can click here to check out her blog.