'See also' section
- I think yes, because it's not a proposition nor discouragement - just a mention. I was looking for shop=philately myself and found nothing on the wiki. If it was there already, I would found collector earlier. We could also collect all the others, like shop=stamps etc, to allow some coordination in the future. --Kocio (talk) 13:20, 3 May 2018 (UTC)
collectable cards / card game cards (sports / Magic cards / pokemon / etc).
While CCG cards are often sold at gaming shops, along with other tabletop games, small 'card shops' also exist, specializing in sales and trading of new cards and reselling rare cards. there are chain shops specializing in these types of cards.
I suggest collector=trading_cards as a value.