A gold trade carries four costs: spread on every entry and exit, commission per lot on raw accounts, daily swap financing on overnight positions, and slippage in fast markets.
On a 100-ounce contract a $0.30 spread is about $30 per lot round trip, which is 10% of a $3 target and 1.5% of a $20 target. Gold spreads widen at the 21:00 to 22:00 UTC rollover and into scheduled US data, which is why scalping XAUUSD is the most cost-sensitive way to trade the metal.