Sure, that screen is tiny, and so is the keyboard, but with 2GB of memory and a 250GB hard drive, that Acer netbook advertised for a mere $249.99 in Radio Shack's Black Friday circular sure looks tempting.

Until you notice that it's running Windows Vista Home Basic.

The ad demonstrates a great temptation that PC shoppers will face as they head to the electronics stores later this week to buy for themselves or for holiday gifts. Many offers will initially seem like screaming deals, but no matter the price, it's important to look closely at what you're actually getting in the process. Not only is that netbook running Windows Vista, it's running Home Basic -- which was the subject of a lawsuit against Microsoft because it lacks Aero Glass and other "signature" features that the company once touted.

"That Vista machine at $249 is no bargain," said Michael Gartenberg, vice president of strategy and analysis at the Interpret LLC research firm, pointing out that many people would want to immediately upgrade the netbook to Windows 7 -- the price of which would effectively wipe out the discount.

Netbooks in general are expected to be a hot item this holiday. For the industry, the trend is evidenced by the fact that overall revenue from PC shipments is expected to decline 10.7 percent in 2009, to $217 billion, even though the unit volume of PC shipments is now expected to rise slightly worldwide for the year.

"Blame this year's drop in market value on the unprecedented declines in PC average selling prices (ASPs) we've seen this year," said George Shiffler, Gartner research director, in a news release. "The rapid decline in PC ASPs reflects a marked shift towards lower price points as customers have looked for 'good enough' PCs at the cheapest price, and vendors have tried to spur market growth by catering to ever-lower price points."

But no matter how low the price, take a good, hard look at the specs and the screen, and try out the keyboard, before you buy a new computer in the midst of a Black Friday shopping frenzy. In most cases, people should ask themselves if they truly need a mobile computer, or if a desktop would suit them just as well, said PC industry analyst Roger Kay, president of EndPoint Technologies Associates.

"You’re going to pay a premium for notebooks," Kay said. "If it's a home system that's not going to be mobile, then a desktop is probably going to be a better deal."

But if you are set on getting a mobile computer, it's worth another look at that Radio Shack ad. Just above the low-priced Windows Vista machine is another Acer that sells for noticeably more, $399.99. However, it comes with a 15.6-inch screen, 4GB of memory and a 320GB hard drive -- plus Windows 7 Home Premium.

Seen any genuine holiday deals, on any type of tech item? Email techflashtips@bizjournals.com, and we'll consider your suggestion for a follow-up post.