Well i was interested in making up a haggle bard, because having shard bank is a great way to get more money selling and saving money buying certain items (potions, etc) for other characters. So I planned my bard around this build to see how it worked out.
As you get very high levels in bard that haggle skill works wonders, if you can approach 100 haggle which i believe would be 50% in selling/buying (200 haggle would be free hehe), you can greatly help your bank account balance.
Now saying that, i found that a normal high charisma bard of this build is still fine with haggle without gimping it in the enhancement department, and your opinions would be appreciated.
To me, picking the negotiator feat before level 20 (changing it out when your bard is complete) and picking haggle skill point bonus also isn't good. Once you reach level 20 anyone can change their bard into a haggle bard after a while with some enhancement changes and a feat change. Until then, your bard is still great with the haggle skill, and having 50 haggle or 44 haggle isnt a huge difference.
So what i did, and i think it worked great. Play your bard as a regular bard, ignoring the extra feats/enhancements that give you the +6 extra haggle (+4 haggle enhancements/negotiator skill,etc). Feats are hard to come by anyway and you will benefit much more from a quicken feat, or extend during your bards life than +2 haggle. Those extra 4 enhancement points do much better in another bard area. MM a quickened disco ball, or +2 haggle.. tough choice..
Then once you hit high levels you can haggle bard your way to that buying/selling machine that you can use to supply endless potions/wands to your other players. Im sure many do this anyway, but just giving some advice to those who want to make a high haggle bard.. a medium haggle bard does just fine and you won't really notice much difference when you reach like 50-60 haggling, and instead you have 44-54 haggle. And then when you hit level 20ish, you can re-arrange what you want if you really want to try and reach 83-90 haggling.
I totally regretted taking negotiator feat instead of a all-game worthwhile feat like quicken/extend. I quickly put my +4 haggle enhancements into something else to help my bard survive until the point where he could approach higher levels. I did lear a lot from this post on building a haggle bard and the skills and such to take. With someone with a shared bank account, i think any newer player should have a nice haggle bard to increase your profit on items and to buy cheaper things for your other characters (bags, potions, wands, etc).