i have a polar ft4. i like it and find it very helpful. mine cost around $100 and i got it at runner's roost.
i am sure i could have gotten something cheaper. i am sure i could have gotten something with all the bells and whistles. the ft4 keeps track of my heart rate and calories burnt. although it would have been nice if it also kept track of distance, it does what i need. straight forward and simple.
do you have one or are you planning on getting one?