With today's high spot price of $1780/ troy ounce (31.1034768 grams), they're worth about $330USD. they hold a high premium over spot for their top of the line assay and quality.
The answer to your question varies because the price of gold varies on a day-to-day basis. The gold price is quoted in Troy Ounces. As of June 30 2010, the price is $1240. This is for Troy Ounce....
As at 4th August 2008 gold stood at US$29.40 per gram (or GB£14.96).
therefore 5 grams would be worth US$147.00 (or GB£74.80)
But don't expect to get the full value for your gold, as dealers...