Rezoning is not an issue if you feel that you will get staff support for an environmental assessment or CUP. I say that becaue it's the EA that will cause you the headaches and that is where the conditions are attached to the approvals.
I agree with Kach that he got the Doctor's Price, but the land entitlements are not too bad if you hire someone with experience. You may get that total cost down.
I also agree that you have no idea yet of your costs. I suspect they will be much, much higher than you are thinking.
Here is a page from a brochure that I made a few years ago for office pads w completed shells that I was going to develop. When the economy blew up in 2007 or so, we put that project on hold. It looks like we might be re-starting it in 2017.
Note that this is for a design build project. You identify your costs much earlier in design build, and can develop to a number. You also can modify parts of your plans such as exterior detailing, parking lot lighting, etc a lot easier that way. If your architect sucks, then try to get subs that play nice, exp. electrical contractor.
