Cheapest outlet for 10?

[nitro498]

Building a computer for this cave. Need suggestions for a Windows OS and where to purchase same. The computer wil be used for surfing and viewing movies. Nothing super fast needed. I noticed on EBay there are dongles available for Windows 10 for $50-$75.
What say you forum?

TIA

 

[abekl]

If you have windows 7 or 8.1, you can install it in the system and do a free upgrade to 10.

Just a thought.

 

[danny123]

With genuine windows, you can upgrade it to win 10. Free update from Microsoft

 

[Puffnstuff]

I would purchase from a reputable vendor and would also consider buying 7 if it is cheaper and then use the software key to install 10.