The main things to take into consideration when buying items out of your country is to take into account what exactly you are buying. Fragile plants that need light will probably not make it to you alive, unless you pay for the really expensive express shipping.
Mosses, moss balls and maybe java ferns will make it. Most other plants will die the 1 week to 2 week (or more) journey.
Sure, it may be cheaper, but what use is a dead plant? In the end, you save more money by getting live plants than taking the risk to save a couple of bucks. That is, if you plan on buying more fragile plants that can't survive long without light.