45 grammes is about 3 Baht weight current value approximately 65,000 Thai Baht. To be valued at 'hundreds of thousands the amulet must be worth more than the necklace which is quite likely.
A tip for the local RTP. Put down you phones. Contact the Department of Land Transport and give them the plate numbers. They will search their database and provide you the names and addresses of the registered owner of each vehicle.
Your welcome......π