In an attempt to keep taxes low some home buyers will specify that MLS not disclose the purchase price.
It’s not a good idea.
The appraisal district, seeing a deed transfer and a non disclosed price will typically propose a value in excess of what it feels the market will support. Appraisal districts may do this to “smoke out” a protest at which the taxpayer (or agent) will be asked to produce the Settlement Statement. If there’s no statement produced then obviously there’s no case for a reduction.
If the purchase price is less than the district’s proposed value then the Settlement Statement will provide evidence for a reduction. But if it’s higher and the Settlement Statement is not produced, watch out! For the consequences of secrecy, read this: