The most famous example of this was the Mirage card Daring Apprentice that had errata after the prerelease but before the set's release (it needed to say the ability could be played as an interrupt it made sense back then)
What Are Triggered Abilities
Not only is he expensive to play, but he's also expensive to buy
Our mana rocks like Astral Cornucopia, Everflowing Chalice, Empowered Autogenerator, Mindsplice Apparatus all generate more mana as we proliferate, our storage lands like Dreadship Reef also become huge rituals, Vat of Rebirth and Lux Cannon get way more effective, we can speedrun through sagas like Phyrexian Scriptures and so much more
Winter, Misanthropic Guide Winter, Misanthropic Guide warps the game with a whopping two extra draws per turn
Proper storage and buying from reputable sources can help maintain the value of your collection