The price of gold changes every business day. At Friday's 6/27/08 close, it was $926.88 per ounce. 50 lbs = 800 oz, so just multiply the current close (from the top-left chart in the link below) by...
Gold prices change every day so any answer posted here would be out of date almost immediately. While it's not normal WikiAnswers policy to say "use the Internet", that's the best approach in this...