I think the avenue of replacment cost of the actual fish of the same size is very, very solid, and not subject to questioning.

That's is probably a better route than I suggested because the time value to make a small fish into a big one is too vague to assign a monetary value.

Excerpt from Robert Crais' "The Monkey's Raincoat:"
"She took another microscopic bite of her sandwich, then pushed it away. Maybe she absorbed nutrients from her surroundings."