It depends on the purity and size of the bar. 1 troy ounce of .9999 gold is at 1209.20 at the moment. The spot price changes throughout the day because of the market. Google "gold spot price" to see what gold is at

Take its weight, multiply it by todays value for gold and there you go. There are different sizes to gold bars.

impossible to say, how much does the bar weight and is it 100% gold?

depends on the mass.