I haven't purchased one online, so I can't help you there. Havahart is a very reliable brand; I do know that.
Ditto to what Janice said about checking the trap frequently. A feral cat in a trap can become extremely frightened and agitated and can hurt itself trying to claw its way out.
Before you criticize someone, you should walk a mile in his shoes. That way, when you criticize him, you're a mile away and you have his shoes.