Does it cost the homebuyer more to be represented by a buyer's agent who serves their interests exclusively? No, because the listing agent splits the sales commission, which is customarily paid by the seller of the home, with the buyer's agent. The sales commission split is usually 50-50, but the listing agent and buyer's agent will sometimes make another agreement and split the commission unequally.
There is one very unusual circumstance in which the homebuyer might pay a commission to their buyer's agent. The real estate agent might show the buyer a local "for sale by owner" (FSBO) home which the client decides to purchase. In most cases, the FSBO seller who is presented with a qualified buyer is glad to pay the buyer's agent a reduced fee of about 3 percent, or half of a normal sales commission. But the FSBO seller could stubbornly refuse to pay the buyer's agent any commission whatsoever. In that case, the buyer's agent would legitimately expect the buyer to pay the sales commission, in fair exchange for the agent finding the FSBO home and negotiating a successful transaction.