The answer to 'how much to fix shut-off valve' is that the cost can vary widely depending on several factors. Generally, the price to repair or replace a shut-off valve in your home can range from $100 to $500 or more.
The main factors that influence the cost include the type of valve (ball valve, gate valve, etc.), the accessibility of the valve, whether the entire valve needs to be replaced or just a part, and the labor costs in your local area. Older homes may also require more complex plumbing work, which can increase the overall price.