Only you can tell at the end of the day. However I think nearly all of us are guilty of thinking we can do a job in half the time it really takes, especially when it comes to quoting. IMO work your price out sensibly, act fiddle factor (10-20%) then DON't be tempted to reduce price because it looks to high. If you do reduce price you won't earn the money you should and will be under pressure to finish quick.