The cost of upgrading from Windows 7 to Windows 8 has been rumored, with Microsoft typically offering free upgrades in the past. Now, The Verge's source claim the cost will be $15.

In the report, The Verge said the offer will run from June 2, 2012 to January 31, 2013 according to a source "familiar with the company's plans." The site added Microsoft Store customers buying a Windows 7 PC from June 2 will be offered a Windows 8 Pro upgrade for $14.99. "The limited time "Windows Step-Up Offer" will run until January 31st, 2013," The Verge added. It also noted the upgrade period will cover the 2012 holiday period, perhaps running alongside the launch of Windows 8 later this year.

Microsoft is rumored to be launching Windows 8 around October 2012, which would be before the typical iPad Christmas rush. Windows 8 is Microsoft's attempt to gain market share in the tablet market, with the Metro user interface bringing the tile-based design to larger screens. Metro is currently used on Windows Phone and the Xbox Live dashboard.

The company will also offer workshops to Microsoft Store customers, who take up the Windows 8 Pro upgrade, to learn more about Windows 8. It will also give consumers a $20 gift card for attending a workshop. The offer will apparently support PCs running Windows 7 Home Basic and above.

Microsoft has previously run workshops for developers, providing tools for developing for Windows 8. The company also displayed the simplicity of bringing apps from the iPad to Windows 8, emphasizing the similar UI elements across the platforms and the greater focus on content in Metro.

CNET previously reported the upgrade offer would begin in June, and claimed then Windows 7 Home Basic users and above would be eligible for the program. CNET, like The Verge, reported June 2 as the beginning of the period which would coincide with the launch of the Windows 8 Release Preview.

With the offer running over the back-to-school period, it could mean new college students will be looking to get Windows 8 cheaply and be incentivised to buy a new PC.