>buy $2k 50 gram gold bar >scratch off 1 gram/trace amount of gold >sell back 50 gram bar for $2k >buy another new $2k 50 gram gold bar >scrape off another 1 gram >sell >repeat until you have your own 50 grams of gold
You could do this for infinity and nobody would know. Why does nobody do this? Niggas are still using those weird river pans to get tiny gold nuggets. Shit could make you rich very fast.
ALTERNATIVELY: buy 50 grams of gold, melt a bit off of it and replace with a common metal like aluminum or iron... re-forge into a 50 gram bar. 25 grams of it would be non-gold but nobody would know because 25 grams of it are covered in real gold.