If you are in the market for a PDA but don't require the most up-to-date model, there's a regular window of opportunity you should be looking out for.Many manufacturers are offering good discounts on PDAs in the month before they launch new products. That might not be surprising - companies have been cutting prices to clear old stock for years - but as competition increases in the PDA market, the replacement cycle is getting shorter and that means the discounts of typically around 25% can be found several times a year and just a few months after the PDA was first launched.For evidence of this you don't have to look much further than what's happening in the market right now: Sony Corp. just cut the U.S. retail price of its PEG-SJ30 by $30 to $270 and the SJ20 was reduced by 25% to $150.The company won't confirm that new PDAs are in the wings for the U.S. market but in Japan and Hong Kong it has already launched an upgraded version of the SJ30, called the SJ33. It's mid-level T665 also got a $50 price cut last week, to $300, just after documents surfaced detailing a new PDA called the PEG-TG50."It's true that the price of PDAs is going down," said Mina Naito, a spokeswoman for Sony in Tokyo. She cited competition in the market as one of the reasons for the trend and said Sony is striving to keep adding value to its PDAs to remain competitive.The Japanese company is not alone. Palm Inc. just cut the price of its Tungsten T model, which hit the market just three months ago, from $500 to $400 and the price of its M515 and M130 models were also reduced by $50 each.In the Pocket PC market, particularly at the low-end, there are also bargains to be had. Dell's entry into the low-cost end of the market with its $250 Axim X5 has shaken up things at the low-end and forced companies to either reduce prices or offer rebates. The latter is a preferred way of discounting for many manufacturers because they know that not all users will end up claiming their rebates.For example, Toshiba's e335 PDA is available for $380 via Amazon.com but that price drops to $255 once you take into account rebates on offer. This competition is on top of the normal discounting that takes place when a product nears the end of its life. Toshiba said it usually cuts the cost of its Genio PDA models shortly before the launch of new models by between \u00a52,000 ($17) and \u00a510,000 depending on the original price.Indicating the fluctuating prices in the PDA market, Toshiba's own Web shop even allows users to have the system send them an e-mail when the price of a desired PDA drops to a certain point.All of this adds up to some great deals on PDAs, especially if you keep an eye on manufacturers and their promotions. It also means you can turn the disappointment that always comes when something you just bought is replaced with a newer model into the satisfaction of knowing that you got a great deal.