Which items do you buy as an investment? I have only been collecting for about two years and I think booster boxes are the best purchase as an investment. This if they have a price between €95-120. They usually achieve this price when they are 8 to 14 months old. I personally look at the price of the cards in the sets, if there are cards that go towards €75-100 (+1 year) I decide to buy a full case. otherwise I stick to 1 or 2 booster boxes. what is your experience?