Windows 8.1 PRO from G2A

[Monte666]

So windows 10 got released few days ago and I got hyped, I want to get my hands on it but there is an issue. I use a pirated Windows 7 
I've done some research and I came across a Windows 8.1 PRO copy for +30 Euros on G2A website that blew my mind
Here is the link : https://www.g2a.com/windows-8-professional-32-64-bit-cd-key-global.html?___store=english 
Now this looks kinda fishy because as far as I remember a windows 8.1 pro physical copy is selling for around 150 - 200 euros. Now I've bought some games trough G2A in the past and all worked perfectly fine, I actually prefer buying keys from third party websites, it saves me some cash too and I still get the same game that's selling on steam for 60 euros for an example
Now back to the topic 
Has anyone bought a Windows 8.1 copy from G2A? 
Is this legit? 
I can't really find the buyers reviews from that product, maybe it does not exist, maybe I just can't find it. 
I want to buy it but I have some trust issues. 
I read trough some threads online and I've found mixed reviews, some people call it a scam, some say it's completely legit, some said they bought keys and it worked completely fine some said the key they got didn't work witch to me didn't help at all cause I'm still confused about all this and honestly I don't feel like throwing 30-40 euros away just like that. 

I really appreciate any help you guys can provide.

 

[FmPhenom]

I have bought two 8.1 keys from that siet and numerous ps4, steam, origin and uplay games. It is fine.

[PetiteBob]

g2a is a legit site i have used it many times

[abdul94]

I personally wouldnt buy from G2A, if you want to look at a non official seller, go to reddit, i hear positive things from there. 
But the best way would be to buy it legit, also the safest. 

[Snickerzz]

I've bought 8.1pro from g2a, no isses. But it's a gray market, you could get a banned key. If you scroll down you can see who's selling the keys and how many ratings they have and theyre successful transactions. But no actual reviews.

[Textosterone]

bought 7 games from g2a but ALWAYS buy shield to protect you against scammers.

[Textosterone]

I personally wouldnt buy from G2A, if you want to look at a non official seller, go to reddit, i hear positive things from there. 

But the best way would be to buy it legit, also the safest. 

G2A is actually safer then reddit. Just pay $1.50 more for shield and if u get a bad key they will replace it for free.

[Monte666]

Thank you guys for the help, I will use the shield I always do. 

[Exploded117]

Been using G2A for a long time. Mostly because they do a lot of sponsoring for CSGO teams and streamers