How many times can you go to a single dress shop?

I selected a dress and put the payment down for whatever partial payment they wanted. I immediately decided it wasn't the dress and asked them to wait on ordering the gown and went in to try on some more. I am completely narrowed down in the style that I want so I am not all over the place, it's just finding something with a couple adjustments from the original one. I had a second appointment and got some more ideas but not sure that one of them is the one. I was wanting to go back a third time. I have been very apologetic and a good client I believe. We gave the stylist a $50 tip the first time, and flowers the second time to apologize for my indecisiveness. She assured me that they were not mad and just wanted to help and how it happens all the time and no one brings flowers. However, my question is how many times is too many times? They already know they are getting about $3000 out of us so I would think it would be okay to go another time. I'm not looking for suggestions on adding an overskirt or making adjustments to the original dress because those are a thought and a consideration. Thanks!