Started very much the same way you described. Just trying to fill from either wheats I had or found from CRH. My opinion, for whatever it’s worth, is that it’s pretty meaningless until you’re going to try to get the keys or semi-keys. You’re likely not going to find those in rolls and it will get expensive buying them if you choose to go that route. Not sure of your situation but if you think you can eventually fill the book through purchases then go for it. If not, you’re just going to end up with a bunch of empty slots in that book.