If you are going to plan for a budget and consultants (staff?) you need to begin with important questions - what is the purpose of this unit (cell?), what are the responsibilities, and what is needed (facilities, materials, travel, etc.) to achieve the goals of the unit? Once you have those details, then you can begin to work on the budget.
I strongly support the responses by Drs. Wolff and Sahu that the first step will be to develop the mission and vision of the "cell", its major functions, the size and care, prevention and specific public health needs of the population to be served. Once that has been done, there likely are some basic formulas for creating staffing and budget data, or at minimum comparisons to other units with a similar purpose and scope.
You are asking the wrong question. The question you should be asking is "What are we seeking to achieve?" The mantra I follow is "Form follows function". Once you know what your job is you work out the logistics of achieving your goal/function.
However also start with a methodological perspective, for example, are we a stand alone or a collaborative agency. If collaborative carry out a scoping study of who else might want to collaborate with you. It is poor management to set up parallel agencies with overlapping responsibilities.
In starting a new cell within the Ministry of Health, addressing public health concerns/issues, it is important to have an overall determination of what are the existing situation and the problems that would be addressed. Developing a problem statement, goals and outcomes which is critical in moving forward with this project. An overall budget, timeframe for starting and completing the requisite core functions. Identifying key members of the team that will be needed and the overall salaries for the team members. Provide each team member with his or her job description and deliverables.