Yes, you can recondition a gearbox instead of fitting a new replacement gearbox. It is often a more cost-effective solution as it doesn't come with the same expensive price tag.
Gearbox reconditioning involves stripping down the whole gearbox and replacing worn or damaged parts to extend the gearbox's life. To keep the cost down, these are often still used parts but they are still of higher quality than the damaged parts.
A technician will inform you during your visual inspection if gearbox reconditioning is an option for you. They will then also provide a quote and a time estimate for completing the repair.