Near Mint Mewtwo cards typically command premium prices, while PSA 10 graded copies can sell for multiples of their raw card value
Old school Adam Rex doing Adam Rex things with a skull in the brown frame that goes into my Affinity deck I still have built
This is also true for damage spells that have a potential exile clause, like Magma Spray
The graded card buyer on TCGPlayer is generally looking for a deal, not hunting for a specific slab
For example, even if we interpreted your library as part of the battlefield for this purpose, slipping one into the card sleeve of a card in your library during a search effectively marks your deck, and that's not allowed
(4) The rights and remedies of Auctioneer under this Agreement are cumulative and the use of any one right or remedy shall not preclude or waive the right to use any or all other remedies Auctioneer may have by law, statute, ordinance or otherwise