Types of examinations, travel to a location (costs per km?), discount for multiple exams?

Pre-employments:

This is a multi-issue examination prior to employment of candidate.

For example:

Questions can be changed to the requirements of the client, but a maximum of 6 questions.

Screenings:

This consists of fixed questions by the client to ensure that the employee is not involved in theft or any irregularities. It is done randomly.

For example:

Diagnostic/Specific:

This is for a specific incident.

For example:

Traveling costs:

This is applicable because it takes the Polygraph Examiner some time to get to the required destination and back to the office. Should the examination take place at the office, no traveling fee is applicable.