As a resident and real estate professional I'm happy to answer additional questions about our town.
I find a more objective view of sales is to compare ACTUAL selling price to ACTUAL tax assessment. This takes opinions, gaming the system and non related items out of the process. Tax assessments also generally reflect value differences due to location, size of property, age of the improvements and other factors.
The BL tax assessor revalues properties every three years on a rolling 1/3 every year. Still the overall BL assessments continue to be HIGHER than actual selling prices. In 2008 the average ratio of selling price to tax assessment was in the 90-95% range. In the past twelve months I have identified thirteen closed sales where this ratio is .8243% (range of .6594%-.9740%). Sand Dollar Real Estate has interesting statistics for the overall island if you are interested.