Pricing information around Windows 8 has been trickling out over the past few months. I've received a new drip of information -- this time about system-builder pricing for Windows 8.

Here's what we know so far about Windows 8 pricing: In June, Microsoft announced an upgrade offer for those who purchasing Windows 7 PCs between early June 2012 and January 2013. For an additional $14.99, these users will be able to upgrade to Windows 8 Pro, as of October 26.

In July, Microsoft shared another drop of information: For $39.99 , Windows XP, Vista and Windows 7 users can upgrade to Windows 8 once it is commercially available on October 26. (Windows 8 testers who have PCs licensed to run one of these previous operating system releases are eligible for the $39.99 upgrade , too.)

This week, one of my contacts passed on to me a new bit he learned about the planned system builder pricing, which will be what white-box vendors (smaller OEMs) will be expected to pay per copy for Windows 8. Microsoft officials also have said the do-it-yourself (DIY)/build-your-own-PC crowd and those installing Windows 8 in a virtual machine or separate partition will be able to purchase System Builder versions of Windows 8 and Windows 8 Pro.

According to my source, Windows 8 system-builder pricing will be largely consistent with Windows 7 system-builder pricing. Windows 8 (the low-end SKU) will cost system builders and hobbyists something just under $100 (U.S.) per copy. Windows 8 Pro will likely cost $20 to $40 more per copy (depending on whether 32-bit or 64-bit), according to information from this contact who asked not to be identified.

In the U.S., the system-builder price of 64-bit Windows 7 Home Premium, originally listed at $129, is being discounted to approximately $90; the 64-bit Windows 7 Professional system-builder SKU, originally listed at $180, is selling for $130 or so at present.

Microsoft is not expected to sell a non-upgrade, fully licensed version of Windows 8 either in a box via brick-and-mortar and/or online retailers. With Windows, full product tends to be quite expensive -- and not very popular, as most users get their Windows either preloaded on new PCs, via volume-licensing deals, or as an upgrade to an existing version of Windows. Very few users want or need a complete, new copy of Windows for a machine on which Windows has not been previously installed.

Microsoft's decision against offering full-version copies at retail may be connected to its desire to curb software piracy. One of my sources said that some DIYers take advantage of "transfer rights" -- allowing users to install and activate Windows on a PC and then call Microsoft and tell the activation officials they changed their motherboard to get them to activate a copy of the software again.

"System Builder copies of Windows 8 will not include transfer rights," said the source, who added that the only way for DIYers to get transfer rights will be to buy Software Assurance from Microsoft.

Update: ZDNet's Ed Bott has some clarifications around Transfer Rights, based on licenses he's seen and analyzed. Bott wrote recently if somone buys a copy of a Windows 8 system-builder license and then sells a PC running that license, there are no transfer rights. But the new Windows 8 system-builder license includes a personal-use license that stipulates a DIYer/hobbyist can buy the System Builder software, install it on one's own PC or virtual machine and keep the right to transfer that license to another PC that the individual owns.

All this doesn't mean Microsoft won't sell Windows 8 at retail at all, however. Boxed upgrade versions, including a DVD, will be sold at retail for $69.99 during a promotional period ending in January 2013.

I asked Microsoft for comment on planned system-builder pricing for Windows 8. A spokesperson said the company had no comment on anything around System Builder pricing for Windows 8.