The giant software Company claims that their launch promotional offer will finish early next month.
Other Windows 8 upgrade options will also undergo a major price rise.
Microsoft has confirmed that both the online and retail upgrades of Windows 8 Pro face a price increase.
According to a company blog post, the Windows 8 standard upgrade will be priced at $120, and the Windows 8 Pro Pack, which will turn Windows 8 standard into Windows 8 Pro, will cost $100. Windows 8 Media Center, currently available as a free upgrade through online redemption, will cost $10.
The current promotional offer will run until January 31st, and costs $40 via the download method or $70 using a DVD. Buyers of Windows 7 PCs between June 2nd 2012 and January 31st 2013 will still be able to upgrade to Windows 8 Pro for $15 until the end of February.
According to submissions to the House Standing Committee on Infrastructure and Communications inquiry into IT pricing which is set to report shortly Microsoft charges Australians 40-50% more for Office products even when downloaded.