As the amount potenially recoverd goes down, you can expect the attorney's cut to go up. For example, in a FDCPA case that might be worth $4,000 inclusive of all damages and fees, you can expect to receive $1000 or less. The attorney takes the balance.
In a $500,000 TCPA suit, the attorney shouldn't take more than 40%, inclusive of all their fees and costs.
As part of any settlement, the attorney should be working toward settling your debt, assuming the opponent owns the debt.