To explain what I was discussing earlier, let's look at an example with the Courtier in my Burnt Offerings game. (Yes you Eloise, pay attention.
She just hit second level, and the important numbers for this exercise are:
Haggle: +4 (2 ranks, +2 Wisdom)
Impress: +10 (5 ranks, +3 Charisma, +2 Insight)
Appearance: +5 (+2 Panache, +1 Striking, +2 Only the Finest, +1 Grooming Case)
The Merchant has Haggle X and Competence III, or +12 and +2.
Eloise starts by talking to the Merchant to improve his Disposition (I'm assuming they both start at 0). This is an opposed check between her Impress and his Competence. Taking average rolls, she rolls a 25 (Rolled 10 + 10 +5) and he rolls a 12 (Rolled 10 + 2) for a difference of 13. She raises the merchant's disposition by 6. She then uses Charming to shift it up another 5. So his Disposition to her is now an 11.
Small talk aside, she settles down to Haggle. Using the same rolls, She rolls a 25 (10 + 4 + 11) and he rolls a 22 (10 + 12). Eloise succeeds by 3, netting a 10% discount or premium. More importantly though, as the scene ends the Merchant's Disposition settles at +6 Intrigued. So the next time she comes back to deal with him she gets another +6 to her Impress check.