If you undercharge for a job, it’s natural that you will be less motivated to dedicate your full capacity to it.
If you charge enough for the job to make sure that your pay meets your expectations for the amount of work, you will be more motivated to produce better results.
But, you still won’t feel as motivated to go above and beyond expectations.
You also won’t have as open of an attitude to scope creep. And there is always scope creep.
If you charge at the limit of what you think the job is worth, it’s likely that you’re undercharging.
You’re missing the opportunity to provide extra value for your customers and more openly accept any scope creep without fuss or attempts to renegotiate.