This is a fun market. It’s in the most central part of Khao Lak near the most popular beach. Here is a video of the beach if you want to see what it’s like. Bang Niang Beach - Khao Lak Thailand 2022 - With Drone Footage ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-VryA3NTi76Q.html
I don’t remember seeing any watches there. Most of what I saw was clothing and food but there could be watches but I just didn’t see any. I also didn’t see any second hand clothing but vendors come and go in places like this so they might be different than when I was there. Enjoy the market.
Most of the stuff you buy at markets like this will be off brand or a cheap copy. It may have a brand name but when it’s 100 - 200 Baht it won’t be genuine.