There are bank spaces for sale in Solomon's Store that are labeled Members bank booster + 50 for 420 RC. When you click on buy, the Restrictions say:
Members: Storage for free-to-play and Members items.
Free-to-play: Storage for Free-to-Play items.
The bank boosters are available for F2P, but you don't know that until you click on the buy button. As a F2Player, I never clicked on it because it was labeled Members Bank Booster. A few days ago, out of curiosity, I clicked on the buy button and to my surprise it's available for F2Players and bought one.
I suggest that on the front of the offer, it should say, "Members
and
Free-to-Play Bank Boosters.