I just played a game featuring the Forager/Pirate Ship combo, and I was quite impressed. Of course, it makes only sense to play it against a money deck. In my game it killed the Storeroom/PStone combo, which is quite strong.
There is some synergy between both cards: Forager helps you thin the deck in order to play Pirate Ships constantly. The Forager gets easily to $2 or $3 since you will eventually trash Silver and/or Gold from the opponent. Since you will often draw together Forager and Pirate Ship, you can start buying Provinces when the Pirate Ship mat is worth $5 or $6.
You may prefer to open Forager/Forager to reserve some flexibility/surprise effect.
