Animate Dead, for example, is weaker to removal, but a lot easier to use in a combo
Massacre Girl, Known Killer Chief: The newest incarnation of everyone's favorite killer clown brings back wither as a way to gain card advantage, but the card design also allows you to reduce toughness in other ways and still get access to card draw
Khalni Heart Expedition
All of these cards are capable of becoming the cornerstone of the right deck, and all have spent time at $20 or more
I play mono-blue faeries, so this list is going to be biased, but with that being said, I have a pretty good idea how all these cards work best
Slimefoot, the Stowaway Slimefoot, the Stowaway snuck into the top 10 and is interestingly only ever really used for Saproling-based decks