There are three ways this happens most often (note that sacrificing or bouncing wont help stop the exile clause)
Card Set(s) -EMPERORS IN THE NEW WORLD- [OP-09] CARD VIEW OP09-003 | C | CHARACTER Shachi & Penguin Attribute Ranged Block icon 3 Effect [When Attacking] Give up to 1 of your opponent's Characters 2000 power during this turn
Instead, it seems TCGplayer Direct has influenced this spike more than outright scarcity
Cards from Commander Legends didn't seem to get noticeably better or worse
Deck parts, large quantity, retired, sold in bulk Bombing Orbit Flyng Pegasus 3 Ruffian Railcar 3 Dynalessler Pancratops 1 Heavy Freight Train Derricrane 3 Bullet Express Bullet Liner 3 Deep Night Express Knight Knight Express Knight 3 Ghost Mourner & Moonlit Chill 2 Ghost Belle & Haunted Mansion 2 Ghost Ogre & Snow Rabbit 2 Eldlich the Golden Lord 1 Jizukiru, the Star Destroying Kaiju 2 Terraforming 1 Zapdos Bolt 2 Lightning Storm 2 Harpie's Feather Duster 1 Special Schedule 2 Urgent Schedule 3 Revolving Switchyard 3 Skill Drain 1 10 extras No.27 IJN Battleship-Dreadnought 1 Heavy Armored Train Ironwolf 1 No.81Psychic crossbow turret train Gustav Max 2 No.81Psychic crossbow turret train Spe Riolu Dora 2 Skypalace Gangaridai 1 Psychic IJN turret train Juggernaut Liebe 2 Engine heavy series Anger Knuckle 1 Total set of 50 pieces
2017 Pokemon Sun & Moon Burning Shadows Hyper Rare Charizard GX #150 PSA 10 Recently Sold for $4,069 [Source] Next we have the first rainbow Charizard card ever released
