That can't be the issue, because then it would still be a profitable strategy until much higher prices. Let's says the price is $1.01m. Sales tax on the $10k is $862.50. Mansion tax on $1.01m is $10,100. The sales tax wouldn't overtake the mansion tax until $130k+ over $1m. I can see a scenario where in an audit they require you to justify the valuation of the personal property, but if that checks out...
I was told via pm that it's considered part of the home sale price and that's why it doesn't work.
Thats why I said if it was close to the $999k number then they would do it. There were many off the books transactions that occurred where people paid cash for the amount over $999k. Sometimes it works in the Sellers favor to have cash (i.e. off the books capital gains) But those days are all but over. No one wants cash these days.
Once you start getting to $1.3MM it got much harder to do this. So there were separate agreements for the RE and for the contents of the home.
If its in the contract of sale then its part of the sale price.