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.