My primary residence is a rental (i pay rent), but if i also own a condo that's rented out. Let's say the condo's purchase price is 400k. How do i determine the actual assessment value used to calculate the property depreciation tax reduction?

Do i just use the purchase price? but for condo i think you have to subtract land / common area from it. Also the cost basis should be market value not purchase price? how do i determine market value with respect to irs' acceptance.

doing your own tax sucks.

thanks