Yes, being a Chinese brand their QC is quite hit-and-miss.
If you're a good shopper you can find KWA's fore under or near $100. I know a bought a KP8 (USP .45) for $50, 100% working condition, too.
I wouldn't want do force-on-force or games unless my opponents had several layers on, this pistol rips through soda cans from 10-15ft away!
That's why we normally use the "bang" kill rule. If someone is within, say, 20 feet, you'd point your weapon at them and yell "bang" instead of giving them a nasty bruise. Also, just because it goes through a pop can doesn't mean it's dangerous. I've been shot by airsoft's equivalent of sniper rifles (around 500 FPS usually), and have escaped with only a small bruise while wearing a BDU.