The answer to 'how much to fix supply line in my area' is that the cost can vary significantly depending on several factors. Typical ranges for a basic supply line repair can be anywhere from $150 to $500 or more, but the actual price will depend on your location, the complexity of the issue, the materials needed, and the experience level of the plumber.
Some key factors that influence the cost include the type of supply line (copper, PEX, or other material), whether the line needs to be replaced entirely or just repaired, any additional work required like drywall or flooring repair, and the hourly rate of the plumber in your local area. It's best to get quotes from 2-3 licensed and insured plumbers in your neighborhood to get an accurate estimate for your specific situation.