Blemished is exactly what it means...... I had a friend who bought 3. They looked perfect. He bought the equally cheap mil type barrels. Well on assembly day the blemish raised it's ugly head. The blem uppers had wrong take down hole pin positions. total junk. He ovaled out the front pin hole to get the pin through on the first one and ended up with a sloppy loose fit.
My advice is that you get what you pay for. I'd rather spend $89.95 and get a 7075 T6 forged upper receiver. I have a complete that I would sell for $400