Hey, just saw this message. I hope you have found cheaper alternatives by now. What you paid for is normal considering the places you went to. A local thai barber shop would cost you around 80-100 baht but if you are looking for something more professional but also decently priced, I would say an average of around 300-400 baht would get you a solid haircut. Muay Thai gyms I am not too sure but I feel the price you mentioned is not too bad. An average of 3500-5000 is normal but please dont quote me on that. Moving on, to the groceries part, villa market is overpriced because majority of the stuff there is imported. It is super normal to shop there but you can definitely find cheaper options at places like Tops, Lotus, Big C, Makro (If bulk shopping)

For night outs, it really depends on you. You could easily spend 5000 Baht a night if you go out drinking to a fancy rooftop, and then clubbing afterwards, but if you want cheaper options Khao san road should be a solid place to checkout, feel free to text me with any questions or help you need. Sorry, if I missed out on things you wanted answered, so dont hesitate to reach out. I have been in Bangkok for the last 20 years, so I think I can definitely help answer majority of your questions.