If you are looking for a flower shop there are a couple in the town, but I don't think you'll be able to find tulips there. You'll find orchids, calla lilies, lilies, roses...tropical flowers.
In my experience as a wedding planner in the area $118 for a bouquet of tulips is maybe slightly on the high end, but within range actually. Two years ago I had a bride request different flowers for each of the 6 bouquet she required, and one being tulips. The price was $110. Just to give you some reference....
Also, I'm not sure what florist/decorator the Royal uses, so hopefully you can see some examples beforehand.
If you do end up finding an outside vendor, just be cautious of the rules at the Royal.
Hope you can find something that will be perfect
Congratulations & Enjoy it!!