I will buy the flowers, but only if I have the money upfront. I have been NOT reimbursed once and that will never happen again. If I stick, say a single daisy, in each tier and call it a day, there is no charge. If I am doing and arrangement, or there are a bunch of flowers, I charge a minimum of $15, but have charged as much as $60. I tell them that it is not what I do, it takes a long time, and I don't like doing it. I prefer the florist do it, I just wish I could see the cake after they go on
I also have a clause in my contract that states that I will not put the flowers on a cake if they are "suspect" in any way (bugs, dirt, poisonous) and I will not be held liable for any flower stuck on there, or for not putting the flowers on there.
And as much as i would prefer to put the flowers on at the shop, heavy roses have fallen in transit, and I would rather not now. I still want them there to cut the stems and put in straws and such, so I don't have to worry about scissors, trash cans, foil, straws, and standing at the venue for 2 hours.