Property tax-Mill rates for MF investing

[Chihiro Kurokawa]

Suppose I'm evaluating a deal and the in-place mill rate is 2.489%. Am I simply going to multiply that by my purchase price in order to calculate my property taxes?

I ask because the broker proforma indicates the following: "Current RE taxes based on actual assessment times the in-place mill rate of 2.489%. Pro forma taxes are adjusted on current revenue to 80% of the sales price. 

Shouldn't they be multiplying mill rate by 100% of the sales price? I don't get it. Thanks for your help!