You and an appraiser colleague are discussing the value of a duplex located in an area that is

experiencing rising demand for mid-rise condominiums. Your friend argues that the sale prices

for condominiums is irrelevant, because you need to focus on what

is, not what could be.

Which principle is your friend ignoring in this case?

(1) Principle of conformity

(2) Principle of substitution

(3) Highest and best use principle

(4) Principle of consistent use

I'm confused because people's answers are all different. Most people say number two or three.