And you have hit the nail on the head of holding gold as an alternative to liquid currency. There is simply no way to reliably buy and sell physical gold at the spot price unless you have millions of dollars.
The stock symbol GLD is an ETF backed by gold. Its shares are redeemable for gold if you have more than 100,000 shares then you can be assisted by an "Authorized Participant". Read the fund's details. Less than 100,000 shares? no physical gold for you. With GLD's share price being $155.55 this would mean you need to have over 15 million dollars, and be financially solvent enough to be willing to exchange the liquidity of shares and dollars for illiquid gold, that you wouldn't be able to sell at a fair price in smaller denominations. The ETF trades at a different price than the gold spot market, so you technically are dealing with a spread here too.
The futures market. Accepting delivery of a gold futures contract also requires that you get 1000 units of the underlying asset. This means 1000 gold bars which are currently $1,610.70 each. This means you would need $1,610,700 that you would be comfortable with exchanging for gold bars, which:
- bear no interest
- are impractical to sub divide into smaller units for transactions
- are difficult to borrow against (although at these amounts, banks can work with you)
- are uninsured, unlike cash in a brokerage account or deposits in a bank
In contrast, securitized gold (gold in an ETF, for instance) can be hedged very easily, and one can sell covered calls to negate transaction fees, hedge, and collect dividends from the fund. quickly recuperating any "spread tax" that you encounter from opening the position. Also, leverage: no bank would grant you a loan to buy 4 to 20 times more gold than you can actually afford, but in the stock market 4 - 20 times your account value on margin is possible and in the futures market 20 times is pretty normal ("initial margin and maintenance margin"), effectively bringing your access to the spot market for physical gold more so within reach. caveat emptor.