If you buy a quality piece you can see more at 20-30x than a lessor one at 100x or more. I've found for the work on razors around 20x shows me all I need to see and to tell you the truth with top of the line quality optics 10x does the job.
Proof of that can be found if you read up on spotting scopes for long range rifle shooting. The quality of the lenses is far more important than the power.