Shopping for back-to-school supplies? Here are tips for scoring the best deals.

Back-to-school shopping is well underway, with more than half of consumers already buying supplies for upcoming classes, according to a survey from the National Retail Federation. With spending expected to reach $38.8 billion, according to the NRF, shoppers may want to do some homework before busting the family budget. 

Depending on the student's age, the tab for back-to-school supplies can vary. The NRF's projections, for instance, include those shopping for college and factor in products such as laptops, clothing and shoes. 

Other related costs include items for the extracurricular activities that 86% of parents report having enrolled their kids in ahead of fall classes. The average cost of supplies, including fees and equipment, comes to $582 a child, a survey by Deloitte found.

Parents plan to spend an average of $586 per child on school items this year, according to the poll of 1,200 U.S.-based parents of school-aged children conducted in May. 

With that in mind, here are some cost-saving tips for back-to-school shopping.

Crayons, glue sticks and construction paper

Website FinanceBuzz offers a rundown of the most expensive and least expensive stores to load up on supplies for kids going to elementary, middle and high school. 

The site added up the total cost of 20 basic items: Crayons, glue sticks, construction paper, markers, pencil box, safety scissors, scientific calculator, notebooks, ruler, binders, loose-leaf paper, folders, backpack, lunch box, pencils, pens, highlighters, combination lock, dry-erase markers and a box of tissues. The average cost of those supplies came to $106.73, according to data the site collected from store websites.

In looking at 10 major retailers, FinanceBuzz found Walmart to be the least expensive, with prices for those 20 common items coming to $67.37, or 37% below average. At Dollar General and Target, those items could also be purchased for under $100, or $70.50 and $83.25, respectively. Fulfilling the list came to $101.60 at Staples, the fourth cheapest store to stock up on school supplies, according to the site.  

Michaels had the most expensive school supplies, with the FinanceBuzz team tallying up the cost at $185.28, nearly three times what it would cost for the same products at Walmart. Walgreens and Office Depot were the second and third most pricey, with the former costing $134.61 and the latter $121.55. The 20 items could be found on Amazon for $119.07, making the retailing giant the fourth priciest. 

Buying the supplies at Meijer would cost $109.25 and at Kroger the tab would run $114.01, according to the site, which noted that both grocers had become "everything" stores. 

Many people choose to shop online at Amazon due to the convenience, but the cost of shipping can surpass the value of some products, leading Amazon to hike those prices. "As a result, school items like crayons, construction paper and rulers are more expensive to buy from Amazon than any other retailer," the researchers noted. 

Research options, discounts

Consumer Reports advises taking the time to research your options, including deals, discounts and price comparisons.  

Another potential cost-saving measure is to ask teachers what supplies are needed right away and what purchases can be delayed, as there are still deals to be found after school starts, the nonprofit advocacy group offered.

Other tips from CR include searching for student discounts, as some retailers and brands run special promotions at this time — and some offer student discounts all year long. Those can include offers on tech, clothing, dorm supplies, phone plans and online subscriptions. 

Also, take advantage of sales tax holidays. More than a dozen of the 45 states that collect sales taxes have holidays from the levy during the summer.

CR also advises those looking for the biggest bang for their buck to spread out their shopping. Wholesale clubs can be a particularly thrifty move for large or multiple families who can divvy up bulk supplies. 

Keeping an eye on sales after you are done shopping can also cut costs. If something goes on sale after you bought it, you might be able to get some of your money back, depending on the retailer's policy. Some allow two weeks for such requests, according to CR. If that approach does not work, you can also return and repurchase the item, the consumer site said.