Spot is the current price gold is trading on the market. Kitco.com has a running price on their site. The market is always moving, it seems, even on weekends. Over and under spot are the rate for buying actual bullion. Despite market price, you almost always are going to pay over spot. APMEX
will buy US bullion gold at 20 over spot and sell at 50 over spot. Other countries trade closer to spot.