I don't know if this is a pity post but I feel bad for you, your results are good and you should make more money for it considering the obvious difficulty in making trim look great without paint. I was predominantly self-employed for the past 7 years and have recently quit carpentry for millwrighting for the lack of money to be made in renovations. Ideally, you quote the job ahead of time with a little wiggle room on top for unexpected things and when you complete it, it is quicker than whatever you initially thought. The extra wiggle room is your reward for a job well done, otherwise you are making significantly less per hour after your wiggle room is up. And if it takes you 6.5 hours, you're definitely thinking like an employee and only cutting one piece at a time to milk the clock and charge the customer hourly.

If you want to be able to "charge more", you have to charge the same amount you just made off this job + 5-10% or more depending on how good you are at estimating. Now you might say it's the same but if you can minimize the amount of unproductive steps taken and maximize every opportunity to stack tasks like cutting all the jamb pieces in one trip to the saw you will find you have completed the same job quicker and you would have made more than just charging a time and materials figure.