It depends on what you are buying. Retail is always going to be higher than OEM. Same as Pro vs. Home, what I am seeing now. $99..99 for Home, 139.99 for Pro now. Last weekend they had Pro set at $99.99 before the launch.
The other night when I looked at Newegg, I swore it was set the same for both. Then again, I was dealing with only four hours of sleep after dealing with the upgrade to 10, causing headaches and having to reinstall the Windows 8.1 image I had.
Microsoft needs to allow Vista machines to get the free upgrade, since the majority of those systems are Intel Core2 Duo, or AMD like CPU's. I ended up loading my test box with Xubuntu, instead of staying with the Insider for 10 on that machine. Makes my life a little easier when I am doing stuff that I need both OS's at the same time.