N-Tier has nothing to do with SQL Server or any other particular product. N-tier architecture can, and should, be accomplished with pure VFP code using VFP data for every system built from today forward.

N-tier means that the responsibilities within the application are clearly divided into distinct layers of objects, no object stomps on the responsibility of another object.

In a pure VFP example of 3-tier you would have a form that does nothing but present data and asks a business object to enforces business rules, fetch data, and update data which asks a database to enforce domain constraints and handle the actual reading and writing to the files.

It makes no difference how small or large a system is for it to benefit in a very big way from N-Tier architecture. Using an N-Tier design allows the encapsulation of code into logical discrete objects with very specific responsibilities thusly making maintenance and evolution much eaiser. It also creates an application where one layer can be changed relatively easily without requiring major changes in other layers.

The N-Tier design does not require that a database server is used, nor that COM/DCOM is used. You can, and should, build N-Tier architectures with only VFP accessing VFP data.

To make the agrument that this client doesn't need internet access today and then design a system that precludes internet access ever without a major rewrite, is like a car manufacturer making a car that can't go faster than 65MPH because that happens to be the speed limit today.