Best and worst things to buy in March

(MoneyWatch) Load up on last year's phones and PlayStation sets, but hold off on buying new applications for your Kindle. That's the best advice from DealNews, a website dedicated to finding the latest bargains.

Best buys

Sony (SNE) is planning to update its popular PlayStation sets, previewing the fourth version of its popular gaming console last week.  So you should be on the lookout for serious price-cutting on PS3 models. In the past when a new console was introduced, the cost of the previous model would drop by 60 percent or more, according to DealNews. That could bring the price of PS3 consoles as low as $144.

A fleet of new smart phones debuted at the Mobile World Congress in February. That makes March the perfect time to consider picking up last-year's hottest smart phones, which could be free -- or darn cheap, if you're thinking of an iPhone. The iPhone 4S, which would have cost you $350 (with a two-year plan) a year ago, for example, will now set you back just $99. And if you want a simple iPhone 4, AT&T is advertising a 99 cent deal. Meanwhile, many of the year-old Samsung models will come free, as long as you sign a two-year contract with your phone provider.

March is also National Frozen Foods month. (Wow! Who knew?) Sure, this impressive designation was made up by somebody's marketing department and is about as newsworthy as Be Kind to Cats Day, but it's got DealNews convinced that the frozen foods industry will launch a bunch of sales to celebrate. If you're a frozen food groupie, it may be time to stock up.

If you've been pining for a big-screen television, the time to buy is nigh. Prices on huge TV sets have been sliding ever since Black Friday in November. Now they're about $100 cheaper than they were then. You could wait and see if they drop more, but at some point the prices start to near the cost of producing the sets. So the 55-inch off-brand model at $550 to $600 may be as low as it goes. Nicer models with 3D capability have dropped to $750 -- the lowest ever, according to the bargain-hunting site.

Prices for Microsoft's (MSFT) new Surface tablet are also likely to drop in March, as an increasing number of retailers start to offer it.

Last, but most importantly, all that Valentine-themed chocolate goes on sale in March. Yum.

Worst buys

You'd think that Valentine-themed lingerie might go on sale in March, too. But, alas, pink panties don't spoil. So, you'll have to wait until June to get in on the Victoria's Secret semi-annual sale, which is also when most other retailers cut prices on fancy undergarments..

Need some new apps for your Amazon (AMZN) Kindle? Don't buy them yet, advise the editors at DealNews. Amazon recently announced that it will start a new "coins" program to make Kindle-application purchases easier. When it launches the program this May, the company is expected to give away millions worth of coins to spark interest in the Kindle app market place. If you wait, the free coins could make your app purchase free.