London gold Vs NY Gold

This is kind of related to a different thread on this forum.

WHat is the difference between buying london gold vs new york gold?

Is it not all in dollars anyway.

Same goes for different types of oils someone can buy.

All Gold is the exactly same, but gold pricing is a 24-hour business, so the only difference between London and New York gold (exculding local retail delivery costs) is time.
Oil is different, oils from various fields have slightly different chemical characteristics. The two main benchmarks quoted in prices are Brent Crude and West Texas Intermediate. The differential between the two is more or less constant so the two prices tend to move in fairly perfect tandem.

Key word here is probably arbitrage.