You "discover" when you finish the process of revealing cards, exiling an appropriate nonland card, casting that card or putting it into your hand, and putting the remaining exiled cards on the bottom of your library in a random order, even if one or more of those actions were impossible for some reason
Like most Magic: The Gathering cards, the value of Eager Construct depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Battlebond)
Known as the card industry's premier third-party grading service, PSA has aggressively improved its technology and broadened its reach in the market since being acquired by an investment group led by Nat Turner, the now CEO of Collectors, in 2021
(It is not, however, Outpost Siege, a mistake an earlier draft made caught by an eagle-eyed commenter!) This deck, on the whole, suffers from Way-Too-Many-Tapland-Itis, and its ramp package barely mitigates that