Some options
If you put all your consumable components into one bag, with a monthly fee, you are essentially replacing one expendable focus with another non expendable focus. The bag becomes the focus. Whats in it is special effect.
Another option would be to keep the components required. They could be carried in any normal pouch. But the player could buy/find/make a pouch that uses any of a number of powers to call on a stockpile of items from some secure location to thier personal location. Access to that reserve of items might come at a price, or the player might need to maintain thier own reserve.
To me, this doesn't invalidate the limitation because the bag could still be removed, or the components on the other end of the bag could be stolen, or replaced for some plot twist. Access to the reserve might require some form of allegiance or duty.
Me, I like the idea that if you are using a consumable, you keep track of it. Gold, Arrows, Rune-pebbles, rations, etc... As GM I do not keep track of these things, but require each player to.
Its not a hard thing to do, its a habit to get into. Just like recording your end use, etc..