>what is the best way between developing first with local views and upsize after and developing directly with sqlserver ?

The best way is developing n-tier application that would bring flexibility in upsizing whether is local views, sqlserver...

If you develop in your application business logic that is independent of data, you can switch to any way you like to store your data.

If you have medium requirements for handling data you should choose native VFP tables (.DBC's) but for big requirements SQL Server is need.

It all depends of your needs.