Play it Again Sports is a local option for selling used sports equipment. They buy a large variety of different types of sports and exercise equipment.
REI has an online buy back program for items that REI has sold including backpacks, hiking shoes/boots, sleeping bags and tents. Items don’t have to have been purchased at REI but they must have been sold at REI. They don’t pay cash but will provide a digital gift card with buy amount to be used at REI stores or websites.