How do I get Windows 10 product key for a new build

[klosxe]

It's been forever since I've had to install a windows OS. My question is how I go about buying a new Windows 10 product key for a new custom build I'm working on. I know that I can create a USB drive with the installer on it from the media creation tool found here https://www.microsoft.com/en-us/software-download/windows10

So how do I buy this product key I'll need during the installation? Microsoft doesn't have the easiest site to navigate... so help on this matter is appreciated. Thanks!

 

[klosxe]

Apparently I'm just an idiot... I figured it out as soon as I posted this.

http://www.microsoftstore.com/store/msusa/en_US/pdp/Windows-10-Home/productID.319937100

 

[Dark Lord of Tech]

PCPartPicker part list / Price breakdown by merchant

Operating System: Microsoft Windows 10 Home OEM (64-bit) ($85.98 @ OutletPC)
Total: $85.98
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-11-19 14:18 EST-0500

 

[Seoulja615]

You can buy it online .. or use any of windows 7 or 8.1 product key that has not been activated on another PC or Laptop.

http://www.microsoftstore.com/store/msusa/en_US/pdp/Windows-10-Home/productID.319937100?VID=320028200&s_kwcid=AL!4249!3!82561416293!b!!g!!purchase%20%2Bwindows%20%2B10&WT.mc_id=pointitsem+Google+Adwords+5+-+Windows+10&ef_id=UwKgqQAABRdc7WY0:20151119191903:s