Mysteryman, I was just thinking the same thing when it comes to the problem of adding an auction house.
So with anything that would usually net us "Free Gran" will net us "Free FM"
Purchases in the store would be like (Set 1 Pack 150 gran or 1500 FM)
If players want gran, they can either spend USD or auction their own cards for gran.
Certain things can only be purchasable by Gran
Card availability increases because people can sell off their non-used cards and use that gran to bid on the auctions themselves
The FM for Point Cards will have to be scrapped into something else. Like more Pt Cards appearing in Lotto and Treasure Battles, and will have the same chance of appearing as a one-star card
Recycle should still net you gran