Interesting approach!
But at 8 grams of gold per aureus, the ~40 troy ounces of gold annual salary is about right.
> In or about 23 BC, with the coinage reform of Augustus, the sestertius was reintroduced as a large brass denomination,
That's 375kg of brass which would fetch about $1700 in today's dollars at scrap prices.
One aureus is approximately $1000 of gold value. And as a collectible item it is worth $3k-10k.
But at 8 grams of gold per aureus, the ~40 troy ounces of gold annual salary is about right.