A good-quality guitar capo will last longer even after heavy use, which means you'll need to replace the components less frequently, saving you money in the long run. However, the most crucial factor when purchasing a capo is its applicability to the guitar you'll primarily use it on.
Always check the fingerboard radius that the capo you're planning to buy has been designed for, as they can vary significantly. While most capos are designed to fit modern guitar radii ranging from 9.5" to 12", there are specialized capos available for different radii.
For instance, a classical guitar capo is flatter to match the traditionally flat fingerboard radius found on classical guitars. By choosing a capo that suits your guitar's fingerboard radius, you can avoid any potential difficulties.