At ~$50AUD per gram, you'd want at least 6 grams of gold to break even, and that doesn't include tools, consumables, and effort put in to extract it...
You can't blame the seller, he didn't set the price. Not completely his fault if people bid too much on his useless junk
To be fair, he never claims how much gold is actually there to be reclaimed.
Also, the layer of gold on these things is ridiculously thin. It's only there as a contact surface so won't be more than a few microns or something thick.