Complex sentence: Imputed rent is the economic theory of imputation applied to real estate: that the value of a good is more a matter what the buyer is willing to pay than the cost the seller incurs to create it.
Split into simpler sentences: Imputed rent is the economic theory of imputation applied to real estate. E.g. that the value of a good is more a matter what the buyer is willing to pay than the cost the seller incurs to create it.