Corey - Congrats on moving into such an educational opportunity. As an architect in Washington State who has done many rezones for projects, I will offer my two cents. First, our process may vary state to state, but jurisdictions need approvals from many different entities to rezone property. While it seems like a simple planning issue, the reality is that each jurisdiction has created a comprehensive plan based on many factors that outlines the goals and objectives for the growth of each community. This plan is reviewed by many agencies (think fire, police, treasury, commerce, city council, mayoral, etc.) that will have to respond to the growth. After much review and revision the comprehensive plan is approved by the city council, mayor, and other elected officials. Changing zoning of any property affects this plan.
So, the planners, hearing examiners and other approving entities need to make sure that the rezone is either in line with this plan or has sufficient reason to go against it, after all they are charged with advancing the zoning in accordance with the comprehensive plan. Further, at least in Washington, the community around the development has a say in what is going on, especially when it comes to zoning issues in their community (unless the project complies outright). So, here, there are multiple community notifications, community hearings, meetings, comment periods, pre-application sessions, and zoning submittals (our land use processes can take up to two years to complete).
Needless to say, rezones are not something that jurisdictions take lightly because they are responding to the jurisdictional authorities (city councils and mayors offices) as well as the surrounding community, which is why it takes so long. My advice, make sure your proposal is really selling the project to the city and surrounding community. Why is it good for them? What will the jurisdiction gain by approving the rezone and what will the community gain or avoid? Try to think about what each entity wants (like jurisdictions rely on taxes) and how your proposal supports that or reduces risk. If the property used to be residential then why was it changed? What is gained by changing it back? One last point, if your project is on the edge of the zoning it is easier to justify to the adjacent zoning than it is if the property is in the middle of an established zoning.
The fees will likely vary per the complexity and how easy it is to work with the planning office. Our fees run in the $5k range for most single family rezones, a few need a civil engineer ~$2k, and the jurisdictions fees vary $5-10k. It may be helpful to discuss this project in depth with the planning office to determine the likelihood of the rezone being approved, and get the economic director to look at it and give you their opinion (hopefully in writing).
I hope this answered your questions. Good luck,