If you got 500$ - 100$ in tax for the card and it drops back to 50$, you can just buy it back with 400$ you still have left...

And a wealth tax and inheritance tax usually have a cut before you even have to pay any tax. Got granny's house worth 500k? No problem. Get a building complex worth millions? Pay your damn taxes. I'm sure the state will accept a payout over time if you can't afford to pay it at once.