Look at that friggin hammer
Perfect Conditions Professional grading is fundamental
As another grindy deck looking to simply outvalue opponents over time, these GB lists are perfectly positioned for that kind of card
Best sources for 1st Edition Pokemon cards: eBay (largest selection of 1st Ed Base Set, Jungle, Fossil, Rocket), high-end auction houses like PWCC and Goldin (PSA 10 graded 1st Editions), Double Holo (authenticated 1st Edition holos), and card shows (inspect authenticity in person)
It trades neck and neck with Blaziken, hovering around the $200 mark in clean raw shape, and as the base sets final card, its often the last ex a master set collector needs
Once in play the persist ability lets the Shepherd sit as insurance against wrath effects for all the non-persist creatures you might have, or any that already used their persist ability once