Just an idea. Why not penalize by percentage? If the goal of penalties is to prevent companies from breaking laws that are equally valid for everyone. Otherwise, companies holding most capital will be practically above the law.
The ACCC usually does do it this way.
Some recent examples: https://www.accc.gov.au/media-release/air-nz-penalised-15-mi... - Air NZ penalised $15m https://www.accc.gov.au/media-release/iphone-and-ipad-misrep... - Apple fined $9m https://www.accc.gov.au/media-release/domain-name-corp-and-d... - Domain Name Corp/Agency fined $1.95m
You'll see that most of these amounts are pretty close to the amount the companies made from the activities and scale with the size of their operations