Answer:
less than $350
Step-by-step explanation:
In economics, the Coarse Theorem for conflict resolutions argues that both parties should negotiate an economically optimal solution regardless of the original property rights.
In this case, Randall earns $350 for playing the trumpet, while Gretchen earns $570 for writing an article. Since both things are incompatible, Gretchen must find a way to convince Randall to stop playing the trumpet, either by paying him at least $350 (which equals his economic benefit of playing the trumpet) or by hiring a lawyer that costs her less than $350.
If hiring the lawyer costs more than $350, then Gretchen should just pay Randall.