Hey Andrew,Just sign up with Listhub.com. They will populate automatically from your mls
It does not automatically change. You would have to file for an appeal usually by the following April after the sale. The sales price is not always a determining factor in whether the town will lower your taxes automatically. There is a sales ratio the town uses from assessed value to market value. Assessed value could be 75% or it could be 110% of market value. Your home has a certain tax ratable value to the town budget and you have to prove you are unfairly taxed compared to other homes of similar nature to yours (footprint of home x stories + footprint of lot, # of bathrooms, fireplaces, etc). Most towns have a margin of error up to 15% either way so that can become a problem too. It depends on the town. Some towns are good when they know that their recent assessments (in the past 4 years) are quite high. Other towns are as tough as nails. Best to check around first before you make the appeal.