Ebay offers Open-Box Garmin HRM-Fit Heart Rate Monitor for Women for $45 (reg $150) with free shipping.

Product Description:
Designed to fit, built to perform. The HRM-Fit heart rate monitor is purpose-built for women — no matter how you move. It easily clips onto your medium- and high-support sports bras and provides accurate heart rate data to your compatible Garmin smartwatches and Edge cycling computers, fitness equipment and smartphone apps. It also captures running dynamics — including vertical oscillation, ground contact time, stride length and more — to help you improve your form. Plus, for indoor runs, HRM-Fit sends pace and distance to your compatible watch. Keep going strong with up to 1 year of battery life.

• Dimensions (Overall): 1.3 Inches (H) x 13.2 Inches (W) x .7 Inches (D)
• Weight: 1.9 Ounces
• Placement: Clothing Strap
• Screen Size: 0 Inches
• Compatible With: No Applicable Model
• Material: Nylon, Plastic
• Battery: 1 CR2032 Lithium, Required, Included