And that's the lower end of the scale for an half decent one!
I got a Sportline one from Target for $90, it seems to do the job well. You input your height, weight, gender, etc and it comes with a chest strap. The ones with a touch sensor only are completely useless.
They are expensive, they are worth it if you want an accurate calorie count, so you know exactly how many calories you get to eat back!