Appraisal done for refinance will be rarely found useful anywhere anytime, except for the appraisor and the bank when the appraisor use it to charge you $3nn (or the refi broker, but eventually, it is you paying it) and the bank use it to justify the disapproval of your loan or make your other trouble for the bank's interest. It is just my opipion, you can certainly give it a try to use it to agree for a lower tax. Let us know how it works if you do use it for lowering tax. Thanks