I'm not a real estate agent, but I don't agree with your analysis. It's a fairly simple logical argument to show why I disagree:
If your supposition were true (the buyer is paying the real estate agent since the seller receives money net of the real estate commission), then the following must also be true:
The buyer is paying off the seller's mortgage(s).
The buyer is paying the seller's transaction taxes.
The buyer is paying the seller's property taxes up to the day of the sale as well as the property taxes after taking possession.
The buyer is paying for all improvements the seller has ever made to the home.
The buyer is paying for all repairs ever made to the home.
The buyer is paying for the seller's increase in asset value.
The buyer is paying for the seller's original construction costs.
Isolating the real estate commission as an added expense to the transaction, while ignoring all of the other costs the seller has elected to incur since the home was built, is faulty logic.
If the supposition that a real estate commission increases the cost of the home to the borrower is true, then all expenses born by the seller in the trasaction as well as all construction, repairs, and improvements have likewise increased the cost of the home to the buyer.
The logic of the supposition breaks down when ALL costs born by the seller that result from the sale of the home are deducted from the seller's gross proceeds because once those costs are deducted, the only thing left is the seller's cost of the original unimproved lot.
In other words, you're expecting the seller to offer the home for exactly what he or she paid for the vacant lot since the decision by the seller to incur mortgage debt, build a house, improve a house, repair a house, and hire a sales professional to sell the house have all contributed to the difference between the original cost of the lot and the price you have negotiated with the seller.
The obverse of your supposition would also then be true: If the elimination of the real estate commission results in the ability of the seller to accept a lower price, then the elimination of the seller's other elective decisions: to build, to borrow, to improve, and to repair would result in a further price reduction back to the original price paid by the seller for the vacant lot.
I don't know about you, but I wouldn't want to participate in a market in which sellers would be required to give away all improvements of a vacant lot to a buyer becuase the buyer felt that the seller shouldn't recover costs to build and improve, costs to borrow, and costs to sell.
But then again, I will gladly purchase any house you have to sell for exactly what the orginal lot cost you, since your decision to build, borrow, improve (and perhaps hire a real estate agent to sell) resulted in you trying to collect a higher price from me as a result of those decisions, and by your supposotion I shouldn't pay for those decisions.
I'm not trying to annoy... I just can't fathom the argument that the decision of a seller to hire a professional to sell a home is somehow detrimental to the buyer since the logic of such a supposition is so obviously flawed.