I lost mine, and need a new cheap working one.
It is probably more than you need/are looking for, but I have a like new Polar S150 with chest strap, bike mount, speed sensor that I am no longer using. If you are interested, let me know, and we can discuss price.
Got an older Sports Instrument HRM (mid-level model) that still works. It’s been sitting for at least a year, so it may need new batteries.
$25 shipped?