We can't imagine that most people spend any amount of time thinking about what they'll do if they ever get abducted. Yet these people do exist, or products like the Ceramic Escape Knife (CEK) would never get made. It's a tiny blade, about the size of a pinky finger and weighing about as much as a penny (2.5 grams), that stays sharp 10 times longer than steel and will never rust. You're supposed to hide it in a place that your would-be abductors would never think to check, and use it to cut your ties if you're lucky enough for these to be made out of something other than metal. It's all of $15, which is a really tiny amount to pay if you ever plan to venture if you're going somewhere unsafe.
Better yet, not going somewhere unsafe is free.