In fact, the main purpose of the bank's gold bars is to preserve the value of investment, so they are generally standard bank gold with ordinary technology, which can be sold by adding a few dollars to the international gold price.
Most gold shops are handicraft gold bars, but of course there are some ordinary gold bars, and the price increases are 10,1g. However, gold shops may prefer exquisite gold bars for their own benefit. Even so, the number of gold bars in a jewelry store is very small, mainly jewelry with high added value.
Therefore, don't compare the price of jewelry with the bank's value-added gold bars. Have you seen the exquisite collection of gold and silver coins sold by the bank by the gram?