pricing cad drawings

I spent 20 years in highway design and land development, being a senior designer at the time I left the business two years ago. I am now in another profession, but recently came across a neighbor who has acreage and wants to develop it into a subdivision. She's asked me to do a subdivision layout, of which I'm very familiar with. However, I spent many years working for a private engineering firm working with big projects but having little input on estimates. I would probably layout a rough design for a 180 acre tract, then when they approve of the design, draw a detailed lot map, using a land survey already obtained and possibly multiple smaller scale maps with a plan and profile of the street drainage. With experience as a professional artist (my current career) I would also price a separate drawing for a color rendering of the lots with green space (it is for an intentional eco-friendly community). Does someone have an idea on a package price for a project such as this... or at least a ball-park price I can begin with for the first drawing? I'd like to give them an estimate of just a simple lot layout of the entire parcel of land and if they choose to proceed further, then I'd have to estimate how many sheets for a more detailed plan and profile of the streets. I have no idea what price free-lance designers charge for such auto cad drawings. I currently use Autocad with Land Desktop 3.

  Quoted Text Here  
[...cut...]
Hello.
Can you analize and evaluate the amount of hours you could spend working on your project?
frank

I am formulating a letter to the land owners to find out what size lots they are interested in. 90 2-acre lots would take a lot less time to design than 270 3/4-acre lots. I was hoping to at first give them a price on doing the initial layout, but I think I need more information from them before giving them a price. I know some people charge a package price or a per-drawing price so I was wondering if there were estimates of that available for this type of project.

I think you should give them an hourly rate & an estimate of how many hours you think it will take you. they may bug you to death with extra details & changes.
  Quoted Text Here  

I second that, since you don't know what you're getting into. The people who charge a fixed fee have to know what they are getting into. If you don't, you have to use a different approach.
If you have to give a fixed price you need to:
estimate how much time it will take have a $/hr number in mind for your time factor in your overhead in $/hr have a contingency built-in factor in some profit for your business
Also draft an agreement that limits the scope of your work, and protects you from scope-creep and makes the client pay for alternates, changes of mind, unknown approvals processes, etc. and get them to sign it. I recommend including a schedule of payments linked to demonstratable benchmarks, and stay one payment in advance in case the clients drop dead, change their minds, or try to stiff you. Specify an hourly rate to apply to work done since the last payment in the event of termination of project cancellation.