CAD makes no difference at all to how a drawing is priced. It can look pretty, but often CAD drawings are no more helpful. CAD is only useful for repetitive work or making complex or time consuming changes
The information for a quote is in the specification text, annotation and number of doors, windows and other items, and dimensions.
No one needs to see a pretty foundation section, they just need to know how deep and how wide the footings are and what construction method is to be used.
Site conditions and access are other factors, and the material quantities are just one of several factors used to build up a price.
Easy Price Pro is no guarantee of winning a job. All it does is quantify materials, and is not a factor in winning work - its just a time saver for the quoter.
A good builder will have done loads of similar jobs and will be able to price new work based on previous work - which is the most accurate way of pricing any job.
All he needs to do is see if, and by how much a job differs from past jobs, and then just work out the difference.
For an extension for example, all the OP needs to do is draw rectangles for the elevations, a triangle for the roof, rectangles for openings and thats it. Then put some dimensions on it
Then he annotates this with construction types, materials, and location of services etc, and any other specifics (like kitchen and bathroom suites) and thats it.