This user may very well be "legit" and provide you with gift cards that work, just note that this user is reselling SCAMMED gift cards.
scammed gift cards come from IRS, virus, craigslist and other various scams. Be aware of what you are buying.
While he may be correct, there is no evidence to fully prove every one of these cards is illicit. That said it should be clear these are eCodes and once they're in your possession it's on you to use them within 24 hours or I will not replace them
So you're saying Milkz may be correct that these cards are scammed from various online and/or phone scams but that he just can't prove it

LOL, at least you're honest.