When a buyer is seeking a buyers agent he or she is looking for legal representation. If those buyers met up with the real estate agent that is representing the sellers, they would have met up with the listing agent. While the same agent may be able to assist the buyers, they have a fiduciary duty to the seller. Hence, the listings agent is representing the sellers and not the buyers.
You would be a great candidate to seek the services of a buyers agents if you met the following circumstances. You have a busy schedule, leaving you minimal or no time to browse the internet for properties. As a result, finding a buyers agent to do the research makes it much more convenient. Perhaps you are a first time home buyer. You may need the guidance of a licensed professional to connect you with an attorney and a lender. You also may be unfamiliar with specific areas or neighborhoods. You may want to purchase the property or unit for investment purposes and only a Realtor in the area would have access to the Multiple Listing Services that would provide all of this information.
Lastly, supposing you wanted to purchase a coop or even a condo for future investment purposes. A Real Estate Agent that specializes in Coops would be able to entertain those requests. Not to mention, that not all lenders would lend on a coop. This includes the fact that not all attorneys have the necessary experience in understanding the financials of coops. A qualified buyers agent is working full time at their position. They are not part timers in the industry. As a result they are committed to working for you full time. They must also have several years of experience in the industry.