You can check out the same ones here on Amazon and it has a few reviews. You can always use an image search to see all the websites selling this model.
Amazon.com: G100 Bone Conduction Bluetooth 5.0 Headset Wireless Headphones Outdoor Waterproof Sport Headset with Microphone for All Phone (Black): Home Audio & Theater
If you are lucky, they are worth NT900 & last a few years, but if you are unlucky they might be dead after a few weeks/months. Those manufacturers buy old or used or counterfeit integrated circuits to save on costs in most cases…so it is a roll of the dice regarding how long they might last.
I’m not sure if Costco neihu still has them, but I saw Aftershokz AEROPEX there for ~NT4200-4500 10 days ago.