Windows 7 upgrades starting at 50 bucks?

Excitement continues to build for Windows 7's October 22 release, but the number of questions remaining about the OS are high. Foremost among them: What will it cost?

According to an alleged leaked memo from Best Buy, it could be a lot less than you think. Specifically, the memo states that starting June 26, Best Buy will "presell... select versions of Windows 7 on BestBuy.com - $49.99 for Windows 7 Home Premium Upgrade and $99.99 for Windows 7 Professional Upgrade."

If the numbers are correct, those are extremely aggressive price points considering Microsoft's notorious history of gouging on prices. Previous rumors had held that Microsoft was eying a premium pricing strategy for Windows 7, which had concerned some analysts that the company might "shoot itself in the foot.

There is, however, a catch: Those prices appear to be temporary, part of a 16-day-only sale that would expire on July 11, 2009; Best Buy gets to hang on to your money for more than three months before shipping you your software. The memo also says that other retailers will be offering the same deal.

As well, if the memo is correct, June 26 will mark the beginning of the Windows 7 "technology guarantee" period. That means that computers purchased between that date and October 22 will have Vista preinstalled but will also come with an upgrade coupon that entitles the buyer to a free copy of Windows 7 when it is released.

In other words: Don't even think of buying a new computer between now and June 26.

Microsoft isn't publicly commenting on prices yet, though it appears on track to do so later this month, possibly in conjunction with the launch of these presell upgrade specials.