Gererally it’s not about back taxes. What typically happened is someone did a deed transfer that needed to list as a sale. By posting $1.00 it qualifies as something of value and makes it a valid sale. This typically happens when family sell to each other. In many states there are also high transfer taxes that are based off of the sales price and by selling for $1.00 they work around the system to evade taxes.
For example I own my home free and clear and I sell it to my brother for $1.00. He then turns around and refinances the home to pay me the actual purchase price.
Another example would be someone who owns a home free and clear and encounters financial challenges. If they think judgements may ensue then selling the home keeps them from attaching to the property. There are many scenarios that this would be beneficial.
There are a few states that do tax sales and don’t include the back taxes or foreclosing liens in the sales price but do collect them from the new owner as fee’s due at sale. But that is a rare case.