^ There were people who managed to collect all. I even met one. Remember that not all fans are that extreme. If you bought a lot of CDs and got a few signed posters (quite common on the day I went, got a signed one myself and managed to trade it for one of Maimai) you had a good base for trading. So with a bit of luck, some might even managed to get the 44 posters without buying 44 discs.
IIRC, they were given a chance to return unwanted CDs & posters after the event got cancelled.