The answer to 'how much to fix supply line' is that the cost can vary significantly depending on several factors. In general, homeowners can expect to pay anywhere from $100 to $500 or more to repair a water supply line, with the average cost typically falling in the $200-$400 range.
The exact cost will depend on the type of repair needed, the materials required, the accessibility of the supply line, and whether any additional plumbing work is necessary. Simple repairs like replacing a leaky or damaged section of the supply line may be on the lower end of the price range, while more complex issues like a complete supply line replacement could be on the higher end.