Gown alterations, payment question

I don't have to make payment until the end when I go to collect my dress, though I was presented an invoice. If theres not a lot of work that needs to be done I can imagine you may have to pay upfront or 50% down. Also if you need a lot of work and shes not very established she may not have some things she would need for alterations (although this may be a tell tale sign to find someone else). If I had alterations that piggybacked off one another then I wouldn't have been provided the invoice my seamstress said. She says its hard to say what all needs to be done from the get go. If its minor fixes then she can but if you need boning then she does boning and finds out after boning it needs tension threading there could be added expenses so she leaves it all open to the fittings.

I paid in full up front

David’s Bridal made me pay in full before they would do any alterations.

I didn't pay until all alterations were done.

I had my first appointment last month, and she requires 50% down at the first appointment. My mom went ahead and paid for the full thing so she could have another wedding payment out of the way, though.

I had to pay it all in full before they started the alterations.

I went to David’s bridal (that’s where I bought my wedding dress from) for my alterations and they told me to pay up front at my first appointment depending on what I need done on my dress.

I haven't paid yet.

I expect to pay when I pick it up. I never pay in full for any kind of work like that until it is done.

I put a 50% deposit down at my first fitting and the remainder is due when I pick it up!