Maybe the intrinsic value of the gold is not the initial profit gained from the sale but more importantly how distributed the coins are? If the man sells to a very wide demographic he then gains a large network-distribution list.
We know that all previous gold mined from Asteroids has had a high impurity lead content, which has slowed trading times due to necessary acid gold purity tests.
I guess the man is hoping for wide distribution so as to gain the highest adoption rate for his new coins. To raise awareness of the coins purity which allows an increase in trading velocity.
There will of course be people who have a mistrust for Gold-Asteroid-mining in general, they may have had a relative or friend who purchased some gold coins from one of the early Asteroid-mining missions, later to realise that these coins were full of impurities, full of lead and the only way to trade those coins was to first sanitise the coin and then undertake a long and arduous gold acid purity test, unfortunately the more these coins were sold the more acid residue would build up increasing the sales time for the individuals involved in the trade. Inevitably these coins became impossible to use due to the time involved to make a trade.
Previous Asteroid-mining snake-oil-salesmen would make many a claim on how they could turn lead into gold making the required acid test redundant, the modern day Alchemists if you will, they would make claims that they would crack the problem of lead impurity once an for all, all the while knowing deep down that it was an intrinsic property of the coin itself, a problem that couldn’t be superficially changed unless physically breaking the coins apart removing the lead and re-minting from scratch. However those who do there due diligence will learn the time saving benefits of trading with an impurity free gold coin. The Asteroid gold rush is surely upon us.