Entomb+ Sire of Insanity + Reanimate or Animate Dead: By reanimating Sire of Insanity from your graveyard, you can create an absurdly complicated situation for your opponents, making the cards in their hands almost nil while filling your graveyard with targets for recursion (note that the earlier this happens in the game, the more powerful it becomes, and this combo can be performed as soon as turn 1 or 2)
The added rattlesnake of "don't attack me, or I'll draw yet more cards" feels pretty underwhelming, but I'd be lying if I said I wouldn't take the cards anyhow
With that in mind I also only cover 15 card packs, that are a non-silver border and in paper sets
Unfortunately, that restriction should keep it in the $5-$10 range for a while
There's usually a lot of math involved, but it's actually extremely difficult to not finish off your opponents if you have an established board state with a bunch of tokens and other small creatures