Some major retailers raise the online prices of certain goods days or weeks before marking them down in seasonal sales events, the NBC News Price Tracker shows.

Walmart is holding a "Walmart Deals" sales event to compete with Amazon's Prime Day. The Walmart Deals event offers discounts up to 50% on various products, including tech, outdoor gear, and fashion.

One more thing I found while ping-ponging around Walmart’s sale pages this week: This OB2 scanner from Nexpow. It’s going for $28.79, a great deal off its list price of $79.99, and has far more functionality than any of the $30 bottom-shelf units you’re going to find on the rack at an auto parts store. Could be worth a look!