Some of the info I posted is based on the past. Some states have changed their rules so an agent can declare himself a seller's agent, buyer's agent or dual agent, and as a buyer's agent, collect his share of the commission from the seller and not violate the fiduciary rules. It has to be declared before negotiations, and the agent will usually have you sign a declaration. Still, once you have started working with a particular agent, it may be too late to engage a buyer's agent. Your current agent has done all the work for you, finding the property, etc., and will expect to be paid the full commision. He/she will take take kindly to suddenly having to split the commision for someone who comes in at the last moment. However, you may be able to talk to the listing agent, explain your concerns, and work it out to have a buyer's agent involved. If the current agent agrees, that's a pretty good sign that they're willing to help you and won't screw you. Then, you have to find a buyer's agent, and you run the same risks of getting a dud who won't give you the proper advice, unless you know someone in the business you can trust. My firm advice is not to use friends or family unless you can be certain they will be professional. More deals have been screwed up by brothers-in-law than by lawyers.
Disclosure: I used to be a real estate agent and had my own brokerage for a while (I also had a boat building company and was a free-lance computer programmer in addition to my bbq grill company - I get bored easily /forums/images/graemlins/crazy.gif)