There's a process which must transpire before you get to cash transactions. Documentation, please. I'm still waiting. We're looking for the gold, remember?
It is a case of the dog that didn’t bark in the night. (A reference to a Sherlock Holmes story).
Mrs Lee sent her agent to pay $92 dollars and change in gold while her husband was a general of the opposing army. The family apparently had, despite being required to pay their debts, free their slaves, and provide for the slaves moving outside Virginia, and despite the destruction of markets due to the war, despite being unable to profit from the property, they had sufficient gold to spare some for the government that they had pretended had no authority over their state. With General Lee unable to feed his soldiers, they had somehow made enough cash to throw it away in what would be treated by some southern partisans as a treasonous fashion. Rather odd that he could make so much money as a farmer without the farm or the farm workers. Quite a stunning accomplishment.
Of course the prostitution business in Richmond was going through an expansion. Most of their business was done in cash, with little documentation. A significant share had to do with interracial trysts. Not having documentation of their transactions would be a positive benefit.
If you see a turtle on a fence post, you just have to wonder who put it there.