[Hondaracer]

I wouldn’t be so quick to discount the costs of “better” insulation and drywall

Sound proof drywall can be triple the price of regular sheets, rocksol insulation is double the cost of pink batts, etc spray foam even more.

Then you get into windows and the more expensive materials, Jeldwen and Starline windows could be triple if not quadruple the price of some Chinese imports. Add on custom sizes or colours and all of a sudden your budget is 3-4 times what you planned without pricing it out