The cost of sharpening a sword can vary depending on various factors, including the type of sword, the condition of the blade, the expertise of the sharpener, and the specific services offered. Here are some general considerations:

1. Sword Type: Different types of swords may require different sharpening techniques and tools. For example, sharpening a traditional Japanese katana with its curved blade and intricate geometry may require specialized knowledge and skills, which can affect the cost.
2. Blade Condition: The current condition of the blade affects the time and effort required for sharpening. If the blade is dull, chipped, or damaged, additional work may be needed to restore it to a sharp and functional state, which can influence the cost.
3. Professional Sharpener: The experience and reputation of the sharpener can impact the cost. Highly skilled and experienced professionals who specialize in sword sharpening may charge higher fees for their expertise.
4. Additional Services: Some sharpeners may offer additional services such as blade polishing, edge re-profiling, or customizations. These extra services can contribute to the overall cost.

As a rough estimate, the cost to sharpen a sword can range from around $30 to $100 or more, depending on the factors mentioned above. It's important to research and compare prices from reputable sharpeners, considering their experience, reputation, and customer reviews.

Keep in mind that the cost of sharpening should be balanced with the quality of work provided. It is recommended to choose a skilled and experienced professional who understands the unique characteristics and requirements of the sword type being sharpened.

Ultimately, the cost of sharpening a sword can vary, and it's best to consult with professional sword sharpeners or reputable bladesmiths who can provide accurate estimates based on the specific details and condition of your sword.