Like most Magic: The Gathering cards, the value of Homunculus 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 (Shards of Alara Tokens)
Being able to take an opponents turn, turn their own resources against them (or the two other players), attack our mutual opponents, and overall set them as far back as possible is a great way to close out games, even if it is a bit rude
Your opponent would then have to find some direct damage or hard removal to stop him from drawing
Look at your top five, drop one onto the field, rinse and repeat every turn cycle
Show your cards to the other player and shuffle them back into your deck