Well. As mentioned earlier, installing a gate is not a cheap investment. It increases in price depending on the materials, height, length, and if it is automatic. So not everyone has the money available to put in a new installation, let alone every time it gets damaged.
We would first recommend you to check how much is the damage. Depending on the climate of your city the gate will suffer to a greater or lesser extent. For example, with heavy rains, your fence should have a strong layer of rust protection. This is to make it last longer and maintain it regularly. If the rust is not too much, it is possible to remove it as much as possible and reapply the rust preventative.