Property tax after purchase

[Account Closed]

I am looking for advice on how to forecast property taxes for my financial model.  The way that I see most brokers represent the property is to take current property taxes and keep it constant or increase it marginally.  Some of the properties that I am looking at have significantly lower property tax valuations than the proposed purchase price.  After I purchase the property, will the property tax valuations true up to the transaction price or do they stay relatively flat?  This could have a huge impact on the P&L.  Any advice would be much appreciated.