For one, it's a fracturefoil, which any card with that treatment will be worth a lot
When Collector Ouphe pops up in a stax list, however, things change substantially
In the cube he is at his very best with sac lands and the like filling up graveyards with lands to eat and his two other tap effects come in incredibly handy in a wide array of match ups
Here is another one that flits past playability kind of near popularity
Again, it's not card advantage in and of itself (since you draw three, and then discard three + lose the Coliseum), but it combines famously with Deep Analysis and madness cards (such as Circular Logic), and its effect can't be counterspelled
Tangled Colony probably works best in multicolor decks where you have access to some direct damage spells, or at least spells that force creatures of your choice to fight.