Bird of Paradise is generally widely available......
Buying from Monrovia is probably the most expensive way to go....I would imagine that you have a Home Depot there, I know you have WalMarts...I would look there first.
I'm used to seeing them for sale everywhere, but that was in SoCal, so it is possible that they may be harder to find in your area...also seems as though anytime I see them at any store or nursery, they are blooming.
If I get a 5 gallon plant at HD, it may be $20...the same plant at a nursery that sells off the Monrovia truck is usually $40.....shop around first.....
