Perhaps I should have quantified "cheap" - I'd consider any lock that's $30 or under cheap, unless you get a screaming deal on something that's normally much more expensive. Good design, good steel, and good heat treatment are expensive, so you're unlikely to get them on an inexpensive lock. If a lock is made with low-grade steel, or if it's not properly heat treated, then it's much easier to cut or break than a lock that is made with better materials and better techniques.