Answer: Ben
When Ben suggests "couples therapy" to Andie, she tells him that she knows a great therapist who will work wonders on him. She actually asks Michelle (her co-worker) to be the therapist, so when they arrive at Michelle's apartment, she is all dressed up like a therapist, has her hair tied back, and is wearing big, thick glasses. She asks Ben and Andie how they will be paying for the session, and when Ben asks how much it costs, she says $300. Later on, after they find out about each other's deals with their bosses, they get into a big fight, and Andie ends up deciding to move to Washington D.C. so she can pursue her writing career. When Ben goes to her office looking for her, he finds her cubicle empty, and the "love fern" sitting on top of her desk. He asks Jeannie (another one of Andie's co-workers) where she went, and she tells him that Andie has just left to go to Washington D.C. On his way out of the office, he runs into Michelle, and asks her, "you're not a real therapist, are you?", to which she replies "no". He tells her, "good job though", and on his way up the stairs to leave, he shouts, "you owe me 300 bucks!".