I beg to differ.
Buyer of private properties need NOT pay any commission. Even if the buyer engage an agent, the sell will still need to pay commission to the seller's agent. The buyer's agent will then cobroke with the seller's agent.
Hence, regardless of whether the buyer is engaging an agent or not, the seller still need to pay the same amount of commission which is already factor into the selling price.
Therefore, it is better off engaging an agent for the buyer as the agent will then protect the interest of the buyer, inform the buyer if the contract terms is unfair, negotiate on behalf of the buyer, etc.