ABC's Dan Harris, Erin Brady and Sally Hawkins report:

When it comes to holiday shopping, this means war.

In the battle for a piece of the $465 billion pie the National Retail Federation estimates shoppers will spend this holiday season, some stores will try to entice people with massive sales promotions and other gimmicks.

However, shopping blogger Dan de Grandpre, the founder and CEO of dealnews.com, shared the top three ways stores will get us to spend money:

1. The Fake Sale or Never-Ending Sale: Stores keep items marked down year-round. Essentially, if it's always 50 percent off, it's never 50 percent off.

"It's the never-ending sale because it is always on sale at that price," he said.

2. The Mark-Ups: Retailers mark-up prices simply so they can mark them down. It makes buyers believe they are getting a good deal when they're not.

3. The Make and Model Mismatch: Stores offer to match a competitor's sales price, but not really.

"Depends on the product, but there is often a technicality, where the model number is very slightly different," de Grandpre said. "That's all they need to be able to say."

4. The Disappearing Carrot: Stores lure buyers in with a super cheap sale item, but they only have a few in stock. So when buyers get to the store, the item is sold out, but then they are encouraged to shop around.

"They get you with the up-sale, they get you with the Blue-Ray player you hadn't planned on buying," he said.

5. The Buy One, Get One: This pushes shoppers towards buying something they may not need, and most of the time the second item that's half off will be a cheaper brand.

Some stores are now even secretly placing special cameras with facial recognition technology in front of display cases, so they can tell what buyers are eye ball-ing as they check out the goods. This helps stores figure out how to re-arrange display cases and get buyers to spend more.

Diana Macdougal, a graphic designer and a semi-pro shopping ninja, explained how shoppers can use the new generation of shopping apps on mobile devices to help fight through the retail war. She recommended Google Shopper, Amazon Price Check and ShopSavvy, which allow buyers to scan the barcodes of any product and see if they can find it online for a cheaper price.

When "Nightline" tested it out, we found one store selling a laptop cable for $24.99, but online, we found it going for as low as $4.79. A Barbie Princess Bride sold for $25.99 at one toy store, but for just $17 online.

As you engage in commercial combat this holiday season, shop carefully.