While the National Retail Federation still thinks holiday season sales will rise a respectable 4.1%, retailers are fighting tooth and nail for every sale in an unforgiving retail environment.

Stores like Wal-Mart Stores (WMT) and Target (TGT) started their deals earlier in November and made the deals sweeter—both retailers are only forecasting modest sales increases this holiday quarter.

Walmart got Black Friday started a week early, with double the number of deals, cutting prices on popular toys, electronics and other gifts, vowing to go toe-to-toe on price with competitors. Others have similarly been more aggressive in 2014.

Market Track created baskets of items from the key pages of the circulars (front, back and key inside pages) at major retailers, and tracked their online pricing so far November, comparing the results to last year. Here’s what it found:

Price changes for these 8 retailers—Walmart, Target, RadioShack (RSH), Sears (SHLD), Kmart (owned by Sears Holdings), Toys R Us, Best Buy (BBY), and Kohl’s [fotune-stock symbol=”KSS”]—have shown bigger swings throughout the month, as well as deeper cuts in the last few days before Thanksgiving Week.

“Prices are so much more volatile in 2014, particularly as we get close to Black Friday- that shows all the competitive pressure, online shopping, and the unprecedented insights shoppers have about prices,” said Ryne Misso, a marketing analyst with Market Track. Technology has advanced such that retailers can more quickly adjust pricing as needed than they used to.

Look how sharply the price index fell over this past weekend at Kohl’s, Target and Sears, as Black Friday shopping got started in earnest earlier compared to last year. In the case of Best Buy, which competes in the particularly tough electronics arena, prices came down early and stayed there.

Walmart uses an everyday-low-price-strategy, which means steadier pricing—this year, prices fell more gradually than other retailers’ but still fell more markedly compared to 2013.

Happy shopping. And more important, Happy Thanksgiving.