@@JennaLea
It sounds like the Chuppa and tulle for $250 sounds about avarage, about the flowers why don't you contact yourself a local flowers shop, since is not as specific? Because $450 just for flowers does sound a little ridiculous, does that include chairs and accesories?
My sister contacted this flower shop : http://florartvallarta.com/galeria-de-fotos/bodas I'll ask her how much they charge her for the ceremony only, but I'll doubt it will be more than $450 usd, I guess it also depends on how may chairs. Also, try asking in spanish that might help out too because as soon as you speak english I noticed prices rise. Let me know how that goes! You welcome !