You have paid retail for the last time.
The human race, to which so many of my readers belong, has been playing at children's games from the beginning, and will probably do it till the end, which is a nuisance for the few people who grow up. - GKC
Does having multiple copies of this benefit you in terms of building decks, etc?
Not for one player; you can only have 1 of any squad or card in your team.
IF you and the other player want the same piece/cards, multiples help.