I feel competent representing both buyer and seller and will let you know if I would feel uncomfortable with the particular parties involved. If you have any concerns, please express them as they present themselves. I would be able to either find another agent to handle the seller or find another agent to handle you, the buyer. Please let me handle the contact with the other agent even if the agent is one that you have chosen. When I make the contact I can request a referral fee from the agent and I would receive a small amount of that agents commission to compensate for the time and effort that has been extended up to that point.
Some large brokerages have a single broker for a large area with many offices.
With dual agency, that broker is also representing the seller. In fact the Broker probably has a longer relationship with the seller and may have even represented the seller when the home was purchased. I would be happy to find you a competent agent even if I am not the agent you have been working with. You should contact lenders or lender to establish a price range where both you and the lender feel comfortable. The lender should run a credit check and possibly pre-approve you for a loan in the amount desired.