Having done many major remodels myself, I'll give you the short answers.
Cost Per SqFt
New construction: $250/s.f.
Remodeling: $300 s.f.
Both figures assume a quality level typical of nice homes in Los Altos of similar quality to Satake Estates. The key is obtaining the best balance of material and service costs which involves knowing where to source them and get good contractors to do the work.
Time To Completion
I've done full home remodels with over-the-counter permits in 5 weeks. That includes remodeling kitchens, bathrooms, floors, windows, doors, etc. but nothing structural. I know contractors who flip homes in Los Altos who can do it in 30 days. It is always assumed that quality is delivered in these efforts as anything less won't fly with Los Altos buyers.
You'll get a better value by having the work done. Buy a fixer and put the money into it and you'll have something you could sell for a profit. This is especially true in Los Altos.