Remember that old saying about buying cheap tools? My first bench vise was a flea market special that literally fell apart when I tightened it, but the cast iron cookware I got from the same guy is indestructible. It's a total crapshoot with that stuff.
Oh man, that's the flea market lottery for you. I bought a "solid steel" hammer once and the head flew off on the second swing, nearly took out my neighbor's geraniums. Meanwhile my three dollar shovel has outlived two marriages. You just never know what you're gonna get.