Hey, congrats for getting your first client. I think its a good decision to not take money from your first client. The experience and social proof you will get from this is very valuable and I think you should concentrate on learning and making as much experiences first instead of chasing money. In terms of how much you can charge, it is important to evaluate how much time the chatbot can save the company. Thats really the value of the chatbot and you have to figure out how much this can be worth to the company. When starting out I would set my prices low and raise them when I gain more clients.