And even if my car is worth $5k, not having to sell it and buy another one (even if I can find it) is worth a premium.
It's likely that something like Harberger taxes could work in certain situations, but not normal people ones.
It also doesn't make the tax onerous; a revenue-neutral switch from our current taxation scheme to harberger taxes would be revenue-neutral, whether it was based on market value or personal value.
Like many people I'm taxed at source with minimal options to change my tax bill. I pay the going rate, as per the rules. Putting the obligation on me to do a bunch of work and worry about correctness would be a huge source of frustration and unhappiness.
If you mess up an income tax, it's easy to get your house taken away and auctioned, with $0 of the proceeds going to you. If you mess up a harberger tax, you get all the proceeds from the sale at a price which you literally just said you'd be happy to sell for.
The frustration and uncertainty isn't nothing; but I think if you were on the harberger system your whole life, and someone asked you if you wanted to switch away from it to the current US tax system, you'd laugh in their face.
In practice the spiteful billionaire will monthly send you offers $10K over the higher of your estimate or fair market value. So you'd be moving every month and incurring all the moving costs continually, or just continually dealing with the legal dealings of such an offer.
The transaction closes and the billionaire just sells the house at a small loss. The situation is asymmetric because the billionaire never actually uses the house.
That doesn't sound so simple to me, everything has to be for sale all the time and\or you over pay on your taxes. Value your vehicle at market rate to pay the "right" taxes, anybody in the market for a vehicle can come buy yours at $1 over market rate if they want to. (It costs 2$ to drive to the closest one being sold at market rate, so it makes economic sense.) The only way to even partially defend yourself is to value your property way over market rate and pay taxes higher than the market value would suggest. Basically you have to value your stuff at market rate plus how much I would be annoyed to loose said item.
Piss off a billionaire? Guess who is never going to live indoors again.