Compare the required feature
A mechanical process uses a tool that must physically reach the surface. A laser process has its own access and focus requirements. Neither description tells you that a particular part can be processed without review. Define the lettering, depth, line width and available area before asking which process is better.
Include workholding in the comparison
The component needs to be located and held during either process. Identify surfaces that cannot be clamped and any existing features that can locate the part. An assembled product may require a different approach from the same component supplied loose. Include its final dimensions and any delicate attachments when requesting a quotation.
Approve the result, not the label
Request proposals against the same acceptance criteria. Compare edge appearance, required recess and any color-fill step that is part of the job. If the drawing mandates a method, the supplier cannot simply substitute another because the result looks similar. Obtain the appropriate drawing or customer approval before changing a specified process.