I've looked at property taxes in different states and some states have a system where tax appraisals are roughly based on actual fair market value, possibly with adjustments which may be distorting (Prop 13, for instance), and those will usually take a completed sale price as evidence of fair market value.

Other states have systems where tax appraisal is routinely 10% of fair market value, and there's some justification for that that never made sense to me. Typically the published tax rates are then much higher than in states with fair market value appraisals. Tax rates as a % of actual market value tend to be roughly similar across states though.