Multitude of ways.  Best way may be to use the built in Alternates functionality with inclusions and exclusions statuses.   You could fashion your Alternates WBS values for changes "Included" and move old takeoff to "Excluded" alternate wbs values.  Feature allows you to change the status of that work break down on s summary screen and see old excluded work on the same spreadsheet - greyed out and not accumulating to the current estimate total.  Going back to include it and exclude something else is as easy as changing the status on the summary screen.

Multitude of ways.  Best way may be to use the built in Alternates functionality with inclusions and exclusions statuses.   You could fashion your Alternates WBS values for changes "Included" and move old takeoff to "Excluded" alternate wbs values.  Feature allows you to change the status of that work break down on s summary screen and see old excluded work on the same spreadsheet - greyed out and not accumulating to the current estimate total.  Going back to include it and exclude something else is as easy as changing the status on the summary screen.

Thanks Mike - Is this for Sage 100 Contractor?  I do not see where I have the ability to change the status or to Include/Exclude anything on the grid.