I used to hoard all of the games, the Pokdex handbooks and the trading cards that I used to build that shrine in my room dedicated to the Yellow Spark Rat
Sneak Attack is second best in this category as the upgrades can be a bit more expensive, but its a joy to play and a fantastic stocking stuffer
At time of writing, each Nazgl art is going for $10 or more, and each of the Witch-kings is going for $4 or $5
Call for Aid has the built-in clause that you cannot kill a player with their own Creatures, and you cannot simply sacrifice them to something like Ashnods Altar, but you can still kill them with a variety of effects
Condition matters a lot Collectors pay for clean edges, strong corners, good centering, and a glossy surface without scratches or dents