Duplex in the TX area - Tax calculation

[Chandrika Vasudevan]

I am a new investor and looking to invest OOS. I'm in the process of buying my first Duplex in the DFW TX area. When I ran the numbers based on the 2019 taxes, my Coc ROI comes to 5.59%. However, my agent stated that the conservative method of calculating the taxes in the area is by running the tax numbers as 2.85% of the Sale Price. This brings the ROI way down to 2.42%.I've attached both the calculations here.

Is this tax rule true in TX? What are your thoughts around placing an offer for this property?