Standalone 810 shows 399.99 or the 510 is 329.99 from performancebike.com and if you are a member you would earn an additional 10% store credit. You could then use the store credit to buy the speed cadence sensor which is 69.99 or the older version of the speed cadence sensor is 47 at amazon. The garmin HRM3 which is the newest soft strap Heart rate monitor is also 47 from amazon.