Windows 10: How to buy a Windows 10 Pro License

What is the best (cheapest) way to buy a new license for Windows 10 Pro for a new build?

The Microsoft store sells downloads for $200.
But Amazon has a DVD for $140.
Newegg sells an OEM version for $140.
So why shouldn't I buy the DVD and use the key to activate a new version from using the Media Creation Tool? Am I missing something?

Any advice or info on this topic would be greatly appreciated.

:)

 

How to buy a windows 10 Pro OEM license?

How to buy a windows 10 Pro OEM license?

 

Windows 10 upgrade license

Hello guys,

I have 1 license of WIndows 8.1 FPP/retail license. I want to upgrade to WIndows 10, but I one thing is unclear to me.
If I upgrade, will WIndows 10 license be retail or it will "turn" into some sort of OEM license?

I ask this because I upgrade my PC, you know, more memory, replace HDD, and I intend to upgrade the MB and CPU to Kaby Lake platform sometime in the future, (and of course sell the replaced hardware)
This thing is not clearly mentioned anywhere.

Thank you.

 

DOWNLOAD WINDOWS 10 NOW - Upgrade and ISO direct from microsoft

Click to expand... Yeah I went to that site, why do I need to buy a key?
I won't buy a key, stupid.

I'll revert back to windows 7 then.

When I still was on windows 7, about a year ago I added 4GB extra ram which is a total of 8GB now,
is that causing the problem?