that win 8 is no way legit. Just run win 10 inactivated.
It's just a product key, so you're not at risk on the actual software since you download that from MS directly. Hey, if it doesn't work, there's a DOA replacement guarantee. If that still doesn't work....it's $8...worth a shot.
While it's "just a product key", the likelihood of it working long-term (potentially even short-term) is minimal.
You'll find countless threads on this very site of 'cheap' keys going wrong. Volume licenses, stolen credit cards etc are all potential sources for those keys - and run the very high risk of being deactivated, or failing to activate outright.
Whether they offer a replacement guarantee or not is a moot point - marketplaces allowing the sale of such licenses in the first place, are hardly likely to be the most reliable/trustworthy themselves.
Given you can run W10 unactivated with minimal restrictions, even $8 seems like a waste.
It's just a product key, so you're not at risk on the actual software since you download that from MS directly. Hey, if it doesn't work, there's a DOA replacement guarantee. If that still doesn't work....it's $8...worth a shot.
If they offer you insurance for an $8 product, shouldn't that be an automatic red flag that it's not legit?