Not to hijack the thread, but here's a hint I've found successful for "generic" floral arrangements (funerals, get-well, mom's day, etc.), not only from the florist I worked for, but others I've used out of state:
Many local florists have 800 numbers. Call, give a price range & ask for "designer's choice mixed arrangement (or bouquet)". I've found you get more bang for your buck. I, personally, LOVE mixed bouquets with a little bit of everything...and you're more likely to get a larger, colorful piece including some high-end flowers.
Don't think that you're getting stuff on it's way out, though. Let's say the florist has a regular order for mixed South American roses - reds & pinks go regularly, but they still get GORGEOUS yellows, corals, bi-colors that the average person doesn't think about. While we would still sell them to walk-ins and phone orders that took our recommendation on good days, it's inevitable that odd "strays" are left with no home except a mixed piece. (Ya have a dozen beautiful reds left that day & the customer wants 6 - what do you do with the other six that are still tight? Mixed arrangement.)
Same with any special orders, such as Charade's pink calla lillies. Many flowers are ordered by the "bunch", thus, to cover yourself for a specific perishable flower, a florist may order a bit extra - which can be used in mixed pieces.
Another advantage of mixed pieces is that the more perishable flowers can be removed as they fade, leaving the "workhorse flowers" behind for a longer period.