Most local shops pay 40% to 60% of retail value on singles they actually want, and they're paying bulk rates ($3 to $5 per thousand) on everything else
Pikachu ex Special Illustration Rare Surging Sparks The most expensive from Surging Sparks is also the defining chase card of the Scarlet & Violet era of the Pokemon TCG: Stellar Tera Pikachu ex Special Illustration Rare
Fire Lord Azula [Borderless Foil] #334 (Magic Avatar: The Last Airbender | Magic Cards) prices are based on the historic sales
Many experienced collectors live by the motto to "buy the card, not the grade," meaning they prioritize the card's actual appearance over the number on the slab
After those, check out the great activated abilities on The One Ring, Strionic Resonator, Steel Overseer, Isochron Scepter, Throne of Eldraine, and Chromatic Orrery
That said, there should be other threads you'll find, pointing you towards history further back in time, such as this one that has been suggested in the comments
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