Like most Magic: The Gathering cards, the value of Thoughtleech 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 (Ice Age)
That means two +1/+1 counters at the minimum, and usually much more than that
What can you say except, Youre welcome
The issue is that the floor of the card (when its only making three or four mana) is still way too high, because Dockside is a card that can be looped, reanimated, flickered or cloned to such a degree that simply making an extra treasure or two is still enough to win the game
The deck's alternate commander is Burakos, Party Leader, who's thankfully a better choice