From the Windows Blog:

 

So here’s the low-down on pricing for Windows 7. The estimated retail prices for upgrade packaged retail product of Windows 7 in the U.S. are:

  • Windows 7 Home Premium (Upgrade): $119.99
  • Windows 7 Professional (Upgrade): $199.99
  • Windows 7 Ultimate (Upgrade): $219.99

And the estimated retail prices for full packaged retail product of Windows 7 in the U.S. are:

  • Windows 7 Home Premium (Full): $199.99
  • Windows 7 Professional (Full): $299.99
  • Windows 7 Ultimate (Full): $319.99

This means that Windows 7 Home Premium full retail product is $40.00 less than Windows Vista Home Premium today.

http://windowsteamblog.com/blogs/windows7/archive/2009/06/25/announcing-the-windows-7-upgrade-option-program-amp-windows-7-pricing-bring-on-ga.aspx