so - here goes - if it were a high quality branded drill set or even a mix, the seller would have mention the name(s). No names, no go. At 10$ per drill and likely Indian made, I wouldn't even call him, as it is most likely a crap deal.
If it were legit, you'd see Cleveland, Dormer, or even some of the better boutique names.
I have an offshore set ending in 3/4 that cost me 40 bucks, or about 5 bucks per drill: and they are hard, and cut well.