It sounds to me like you are doing more than a basic detail job and should charge a bit more. This sound more like a show prep and the local shops qualified to do such work charge closer to $500. Plan on having the car from 2-3 days and don't go too fast. You also mentioned a polish, I would only use this step if you are trying to remove fine surface defects in the paint, not as part of a normal detail job.
step by step:
wash, use dawn dish washing detergent, this remove all old waxes and surface contaminates, 1 hour
claybar: 2 hours. minimum, my car took nearly 4 hrs to do correctly.
interior with vacuum and full detail, 2 hours
wheel detail: 1 hour unless wheel removal and back sides done, then 2-3 hours
If you are going to polish it add 2 hrs.
each wax/sealant coat 1.5 hours. so three coats 4.5 hrs
engine detail: 3 hrs.
Right there your looking at, say 15-17 hrs, and at the above 30/hr that would be $450-$500 adding costs of materials and $550 isn't to bad a number. Any shops that charge less are not claybarring the car, not removing wheels, not doing engine compartments, one coat of wax on unprepped paint etc. Quality work costs money and if you are doing the job correctly (it sounds like you will) then make sure you get paid correctly.. just my