I agree that sounds very low, but I don’t know your area or your skill level. My advice is to get a stopwatch and wear it around your neck. If you are working on the cake, let it run. If you stop for lunch, talk to the mailmna, pick up the kids, etc. then pause it. It might not help you price THIS cake, but it will let you know the exact time you are spending on your cakes. It is very easy to lose track and you guessitmate it took 10 hours when the actual time was 16. Big difference!