We currently don’t have a good way of reducing the amount of experience we get (leveling up while not having good cards being a negative to many new players). What about an armor set for 500 gems (or less) that has a cursed theme?
“Armor of the Cursed Tombraider” or something. The lore can be that it’s original owner got cursed while looting a tomb. Since it’s a tombraider’s armor, maybe it lets you spot treasure easier, but not as good as Dragon Armor. Something like:
-50% Experience (cursed)
This would also help people who want to negate the +50% experience boosts that comes as a result of winning a GW match.