Adding a story, worth it? Estimating

[Trevor Blount]

I'm in the midst of renovating a property in a high end neighborhood. The size of the house is 3500 sqft, single story, and only a 4/3, and rather small at that BR/BA count for the neighborhood. 

One option I'm considering is adding the equivalent of a camelback, or second story over one side of the home, adding ~900-1000sqft and 2 or 3 bedrooms. 

I'm having a hard time finding any estimating tools for this kind of a project, adding a story and multiple BR/1 BA, and wondered if there were any tools, sites or recommendations any of you have for this kind of a project. 

Thanks for any and all advice!