it would be hard to know without knowing purity as it could be a huge difference from 10k to 24k. Could be 10 bucks, could be 80 bucks..
Also, are you sure its gold? Is it the stuff from ebay or is it fine placer gold? Ebay flakes are usually fake. Placer gold is usually 85-95% pure depending on location and even though its not pure can usually still get spot if fine and higher price if larger gold.