EverChanger
エヴァーチェンジャー
Look forward to a free trial period after the launch of Pokémon Bank. Be sure to try out the software for yourself during this time to see everything that Pokémon Bank has to offer!
-The XY Site
Just transfer all the Pokémon you want during the trial period and you don't have to pay a cent. Besides, I'm sure Game Freak thought long and hard about charging for this service. I'm certain that a circa $5 annual (as in, per year) fee is only what they deem absolutely necessary to beef security on this service and cover development and maintenance costs. Game Freak has never intentionally screwed us in terms of money in the past, and I highly doubt that they'd begin doing so now.