How to pay collaborators to the service business with little money? [ADVISE] I will not promote

hello pals I have an idea to do as a "marketing agency" or something initial, focused on professionals who know a lot about their jobs but dont know anything about how to promote and sell themselves and therefore is very bad economically.... currently I have my medical practice and because of my knowledge in digital marketing and sales we are never out of work thank god and I know how I can help them, but I cant do that work for others to lack of my time. so, I would have to hire collaborators who know web design, video editing, web development as basic... i have the idea of what could implement for most of the problems to generate sales to those professionals, the problem its I dont know how I could do to pay to the collaborate person whos gonna to help me to start this "entrepreneurship" at the beginning, because customers "at the beginning" would not have how to pay a monthly fee, or will be very little, like 150usd each client... With the promise that in the next month we increase the payment, let's say double. important! It is only an idea because I have not spoken anything with any client, therefore I do not know if they could pay more at the beginning is just an idea to have and how to start in that scenario. so I do not know what business model I could implement at the beginning... any advice?