The $21.75M purchase last week of a prime downtown block adjacent to Republic Square for a new 17-story Travis County Courthouse exposed problems in the county's tax appraisal accuracy. If you look at the historical tax appraisal data for the downtown lot, the appraised value was clearly significantly below market: 2005 Value: $7.6M2006 Value: $7.6M2007 Value: $7.6M2008 Value: $7.6M2009 Value: $7.6M2010 Value: $13.9M2010 Purchase $21.75MThe actual value of the lot -- confirmed through an independent appraisal which determined the fair market value for the transaction -- was 56% higher than the current . . .