I strung a cheap aluminum racquet that folded on me like a cheap suit. To this day I don't do cheap aluminum racquets cause if it's not perfectly round or even if there's a slight dent it can fold on you.
Also I turn down all cracked and worn out racquets I refuse to string them. Its just not worth my time. Also how bad are you to wear down a racquet till i'm able to stick my finger tip inside the frame.