I have found that the key is to do your own research. Check with your local technicians, ask for recommendations, and don't hesitate to get multiple quotes. I have found that the cost can vary greatly depending on the condition of your piano and the quality of the strings you choose. For example, premium strings will naturally cost more, but they can greatly improve the overall sound quality and extend the lifespan.The cost of retuning a piano can be puzzling, but there is a way out, just check out
https://melodyguide.com/ , a fantastic guide to musical instruments.I used this guide to learn about the different types of piano strings and their effect on sound quality. I also found a detailed section on how to evaluate a technician's experience to be extremely helpful.