Recently my friend bought coin-operated gold bars. What is the difference between this and ordinary gold bars?

Shangbi Gold Bar is a gold bar produced by Shanghai Mint and sold by Shanghai Shenquan Industry and Trade Corporation. Specifications are 10g, 20g, 50g, 100g, 200g, 500g. The price is the gold price plus 8.9 yuan/gram -9.9 yuan/gram processing fee, which can be said to be the lowest in the market. Different from other gold bars, they also have collection value, including their gold coins, and they will also launch a series of sales and distribution from time to time, and they are well-made, which is an investment way to kill two birds with one stone.