"Mattresses are not good buys in January," says Sharon Banfield, director of public relations for PriceGrabber.com.
Expect better deals: in February. "Most of the sales occur over the Presidents Day holiday weekend or July Fourth holiday weekend," she says. "That's significant for a mattress -- it's something people have for a decade or more."
What you can save if you wait: "at least 30 percent," says Banfield.
Likewise, if you're considering buying furniture but don't need it right away, you may want to wait a few weeks, says Michelle Madhok, founder of SheFinds.com.
"The new models are coming out in February, so the furniture won't be on sale until February," she says.
What you can save: up to half off on some of last year's models, says Madhok.
What is on sale in January: holiday trimmings. From wrapping paper to ornaments to home-decor items, "You can save 70 (percent) to 75 percent," says Banfield. "It's very substantial."