Frugal shoppers love to delay a purchase at the retail or online store, waiting until the retailer lowers prices. The strategy often pays off. For many years, Christmas shoppers have waited until mid-December or later, thinking that the retailer will slash prices or risk having to take bigger markdowns Dec. 26.

Back to school shopping is different, according to Carrie Rocha, founder of Pocket Your Dollars, a money-saving website. "Don't wait until the last minute," she said. "The sale fliers start after the 4th of July and the prices are good," she said.

She gave the example of SwissGear backpacks at Office Depot, on sale for $10 (regularly $29) through Saturday (July 22, 2017). Rocha said it's true that some retailer will probably have a $10 backpack in late August, "But they're cheap. They're not the ones you want," she said. In Target's Sunday flier, for example, it's least expensive backpack is $15 while others are on sale for $28 to $35. The Office Depot deal is a good one.

Rocha sold her website on July 1 and unfortunately the new owner is not planning a back to school price comparison, but you can still look at the chart Rocha compiled last year with best prices for common Back to School items.

When Rocha says to shop in July, she's talking about all BTS items from erasers to computers. For even more savings, check the coupon fliers in the Sunday papers too, which have recently included coupons on Mr. Sketch markers as well as a rare Ikea insert for $25 off on an Ikea purchase of $100 or more.

Rocha knows a low price when she sees it. The best time to get deals on Halloween candy is in September, not October, she said. Who knew! Course you can usually save 50 percent or more shopping for Halloween candy at Target on Nov. 1. The selection may not be the best, but when buying candy, a good selection is not always a good thing.

One more bit of wisdom from Rocha: Despite what we might think, ads for Back to School shopping are not creeping earlier and earlier like Christmas. The big BTS push starts after July 4 and that has been so for the 8 years she's been tracking it. Christmas, on the other hand, can now start before Halloween, not to mention the Christmas in July sales.

I'm looking forward to more of Rocha's shopping wisdom in her new gig, whatever that may be.