How to determine the FMV for a 2unit townhouse I purchased and rent half

[wgb317]

I purchased the townhouse I previously rented, but I purchased the entire 2 unit townhouse.  I Now rent one half and live in the other as a resident landlord.  Would the fair market value be based on the purchase price?  Or would it be as listed on my Property Tax bill as the Fair Cash Value?  Obviously the price I paid as the fair market value is higher than that as listed by the taxing district for the fair cash value.  I opened a help session earlier with a Turbo Tax consultant and she had stated I would, and I believe this is right, enter the FMV as 50%.  So my question specifically would be, is my FMV 50% of the price I paid, or would it be 50% of the fair cash value listed on my property tax?

[Mike9241]

for rental depreciation purposes you use the lower of your total cost less the land cost or Fair Market Value less land FMV when you start renting. assuming each 1/2 is virtually the same depreciation would be based on 1/2 the of the lower of the two values.  Property tax bills can be notoriously unreliable as are certain websites that offer valuations and potential sales prices.  Asking a realtor in the area would be a good idea. However, I would skip even that if you have reason to believe the property would sell for more than what you paid.