It shortens the lifetime. And since you play everyday for several hours with plastic shuttles, want exaggerated durablity because of financial issues you are not in the position to make wishes, you just need to realize that there is just one way to find a solution: a) I don't have the money for frequent restrings, play plastics, play badminton every day -> Thick string and low tension b) I have money for frequent restrings and can use whatever I want at any tension and can go for thin strings You are in a) and in a deadend. Take what we suggested in several posts. Anything else don't fit your requirements. If you are allowed maybe you get an option to find something to earn a bit badminton money. Like helping in the household more or do private tutoring if you are very good in school and so on. Also talking with your parents honestly that you want to earn some money for your badminton passion can help. If parents realize how important something is for their children, they struggle to be strictly and will find with you together a solution.
The answer in your case is quite easy...just pick a medium thick to thick string that you like, eg. BG65, ZM69F, etc and play with it until it breaks. It may take 2 months, or it may take 8 months, but eventually it'll break and that's when your coach will tell your dad the racket needs a string job... Sent from my SM-G965W using Tapatalk
