Assessed values are voodoo - based on estimated market value and influened with factors used to establish a tax rate. Rarely reliable and very subjective - and remember, most people want low assessments and will not report material improvements that might raise assessed value.
The sale of a property determines market value in the market of the moment. Often, one person's opinion of market value conflicts with another person's opinion.
Assessed value is the weighted estimate of value that is the basis of a property tax assessment from the city or county of record.