There is an amulet market where a huge selection of amulets are being sold. When I was there, I saw mostly locals buying amulets from there and literally no tourists. I have been told that many of the amulets were sourced from here.
Sometimes you have people buying amulets from here for a cheap price and then passing off to unsuspecting people that it is a special amulet, therefore selling the amulet for hundreds of times worth the original value.
The amulet market is located within the compounds of Wat Ratchanatdaram in Bangkok:
It is just opposite Wat Saket วัดสระเกศ (Temple of the Golden Mount).
Wat Ratchanatdaram วัดราชนัดดารามวรวิหาร
2 Maha Chai Rd, Khwaeng Wat Bowon Niwet,
Khet Phra Nakhon,
Krung Thep Maha Nakhon 10200, Thailand
Location: located at the intersection between Ratchadamnoen Klang and Maha Chai Road, in Phra Nakhon district, Bangkok.
Opening hours: 9am to 5pm
Entry fee: 20 baht if you are visiting the temple premise but free of you are browsing at the amulet market.