Ideally you're correct - but it does have the very large side effect of making real estate fraud much more lucrative. This isn't to say that the potential of people breaking a law means we shouldn't have the law at all - but higher property taxes necessitate a much large spend into property value auditors and require a lot more stringency around property improvement permitting to ensure that increases in property value are captured and recorded accurately.

How much fraud we talking? I like to think along Matt Levine's ideas that at least some amount of fraud is acceptable - there will always be some amount of it and under or over-regulation creates a net-negative.

Tough to measure. A couple data points:

-NY state estimate $150–200M per year lost to real estate transfer tax fraud and evasion. On $3B receipts that is 5-6% breakage.

-Harris County (Houston) found $21M in improper homestead exemptions. On ~$7B receipts that is ~0.3% breakage

-Miami-Dade found $35M on $6.5B for improper homestead exemptions, 0.5% breakage

For comparison, IRS net tax gap is about 12%

One would expect transfer tax fraud/evasion to be an order of magnitude different from improper homestead exemptions.

For sure. Probably should be using the total homestead exemption eligibility as the denominator instead of prop tax receipts. Even then transfer tax is a "hill" and the homestead exemption is a "valley." But It's hard enough to estimate any of this data from a keyboard in a few seconds

Except the property taxes aren't based on the actual price paid. The tax assessment and appeal system is more prone to corruption than most states.