Playing only one Sacred Foundry is self-explanatory
(As of right now, only Espeon ex, Vaporeon ex, Jolteon ex, and the previously revealed Flareon ex and Eevee ex are translated.) I feel like espeon is not weak at all, forcing your opponent to re-search all of their evolved Pokmon is pretty impactful especially against pidgeot reliant decks or ones that use mid-stage evolutions such as kirlia or drak as draw engines
However, MP and LP copies don't fetch the premiums you might expect, as they cap out at around $40
If your lifegain deck struggles to close things out, you probably need more payoffs
Green decks almost always have the biggest creatures, so you dont need to worry about your opponents drawing too many cards off this mana and card advantage engine
The cards value is determined by: Rarity symbol (bottom-left corner) Set number (Secret Rare check) Artwork and Pokemon identity (visual) Card texture (feel it premium cards have embossed patterns) The Japanese text describes game effects