cards in your cost area

7.2/10$0.34 Fly Enchantment Aura Enchant creature Enchanted creature has flying and "Whenever this creature deals combat damage to a player, venture into the dungeon." (Enter the first room or advance to the next room.) 7.2/10$0.34 Fly Enchantment Aura Enchant creature Enchanted creature has flying and "Whenever this creature deals combat damage to a player, venture into the dungeon." (Enter the first room or advance to the next room.) 8.3/10$0.32 Staggering Insight Enchantment Aura Enchant creature Enchanted creature gets +1/+1 and has lifelink and "Whenever this creature deals combat damage to a player, draw a card." 8.3/10$0.32 Staggering Insight Enchantment Aura Enchant creature Enchanted creature gets +1/+1 and has lifelink and "Whenever this creature deals combat damage to a player, draw a card." 0.8/10$0.19 Coral Net Enchantment Aura Enchant green or white creature Enchanted creature has "At the beginning of your upkeep, sacrifice this creature unless you discard a card." 0.8/10$0.19 Coral Net Enchantment Aura Enchant green or white creature Enchanted creature has "At the beginning of your upkeep, sacrifice this creature unless you discard a card." 8.1/10$0.26 Security Bypass Enchantment Aura Enchant creature As long as enchanted creature is attacking alone, it can't be blocked

There's also always the risk that one of their creatures will be the wrong color, or it will fly, or something similar will go wrong, and the creatures that can't attack are still around to prevent you from winning the game in the meantime
You could also slap on a Basilisk Collar or other source of deathtouch
The ratio of border to center of the card can determine how high the card is graded
That said, dont count on unbans