Some theft is efficient. If a hypothetical thief grabs a few bills from an unattended wallet, and the wallet's owner wasn't counting on having a specific amount of money available soon after, the amount lost by the victim is roughly equal to the amount gained by the thief.

Stealing copper from power lines and transformers is among the least-efficient kinds theft; it's hard to do worse without shooting a wealthy philanthropist couple to steal a wallet and a pearl necklace. I have seen a term suggested--the "rapacity index"--for the ratio of value gained by the thief, to value lost by the victim. I think it makes sense to take a crime's rapacity index into consideration during sentencing.