I have a PC1600 - It has all of the features I need including Time
in/above/below zone, average and max HR, calorie counter etc. I
actually got mine for $29.99 at Performance (locally in the Bay Area) -
I am not sure why the price was so low, but I was not complaining at
the checkout.
One side benefit of the Sigma - I actually bought this as an exchange
for a Polar s-150 HRM, which I found suffered from horrible
interference and inaccurate readings, the Sigma has fixed that and is
much easier to use also. I highly recommend them, especially for the
price