I would negotiate a lower purchase price (in a down market you can, especially if you're a willing and able buyer). I don't really care how the agents work it out. That will immediately lower my property taxes and pay me back a little bit every year for as long as I own the house. If there was a way to work it out, I'd be willing "rebate" money to the seller and pay all closing costs just to get a lower property tax basis.
You can easy calculate the "rebate" that you want and lower the purchase price accordingly. Be ready to walk if the parties can't come to an agreement.
I think that each buyer is different. Some buyers like to be presented lists of houses to visit and have someone walk them through the purchase process. Other buyers know that they want and are capable of finding their own house. I fall in the latter category. When shopping at the mall, I'm very irritated when the salesperson wants to help me or makes suggestions. I just need someone to find my size when it's not on the rack.
Sad to say but most people would rather have the extra service because that makes them feel good, although they have to give up something else for that service.
The main problem with negotiating with agents is that most buyers rely on the agents who work in conjunction with loan, title and escrow officers to "get them into" a house. They are ignorant of the process and can't afford to push for a better deal, lest they "loose" the house they want.
I like the way exeunt put it: I would rather pay for a boat in MY driveway rather than the boat in HER (the agents) driveway, wouldn't you?
Since I'm very familiar with RE transactions, I would have no problem going with a discount brokerage such as Zip Realty for a purchase I have already identified. If I needed hand-holding or suggestions on where and what to buy, I would use a full service broker (who charges discount commissions) such as SD Realtor. I think that SD Realtor has a good business model for the future — kinda like the Southwest Airlines of Real estate; you get everything for a lower price. Well, you get peanuts for lunch on Southwest, but you wouldn't eat the food on American anyway.