As one of its daily deals, Amazon offers the Withings Pulse O2 Activity, Sleep, Heart Rate & SPO2 Tracker in Black or Blue, model no. 70031601, for $79.99 USD with $6.56 USD shipping. That's the best price Dealnews could find by $33 and an all-time low. It tracks steps, elevation, distance, running, calories burned, heart rate, and blood oxygen level, and features real-time coaching via the companion Health Mate app for iOS and Android.
The next cheapest retailer sells it for $145 shipped. The Apple Store sells it for $180.
The Withings tracker is basically a Fitbit with a heart rate & O2 monitor. Reviews on Amazon seem like people either love or hate it. Good review from Engadget.
Activity tracking: steps, elevation, distance, running and calories burned
Wear it your way: clip and wristband included
Vital signs reading: instant heart rate and blood oxygen level
Sleep monitoring: sleep cycle analysis, wake-ups, total duration
Real-time coaching: in the free Health Mate app (iOS/Android)
Estimated delivery: Feb. 3, 2015 - Feb. 6, 2015
Via Dealnews
These are great - i have the one without the wristband and it is very accurate. Well supported by Withings and continual updates and improvements for the Android app. Battery life is excellent as well at 7+ days. IMO beats products like Fitbit, Jawbone as it offers heart rate and O2 monitoring.