Just some comments from someone who previously sold real estate.
First, the buyer is typically asking for a concession that will be used for paying points to get a better interest rate- usually because of qualifying purposes. The seller couldn't care less if they are giving money to the buyer in the form of cash at closing, or just by reducing their sales price. The Realtor will be doing a seller's net sheet for the seller and it all comes out the same for the seller, Yes, the seller sees cash to the buyer as no different than reducing the sales price, and I never once had a seller who made such a distinction. That's why there's almost always a one-to-one relationship between the concession and adjustment amount.
The rare circumstance is when you have a buyer with poor credit who really needs a large interest rate buy down or more down payment in order to qualify. Jumping to the next % level of down payment to avoid PMI can also help them qualify by eliminating another set of qualification guidelines. If that buyer finds a seller who is willing to do an unusually large concession, then that seller can usually take advantage of that situation by getting a much higher sales price in excess of the concession amount. Many times this is done without the lender's knowledge if the concession amount is in excess of the qualifying guidelines.
I personally never got involved in that aspect because that action is most likely illegal for the buyer to fail to disclose the concession to their lender, but it unfortunately happens too often. I never figured out how agents pulled those sorts of transactions together anyway, because the cash to the buyer would happen outside of closing and not be documented anywhere. The buyer could get ripped off after the closing and not have any formal written document showing what had been agreed to between the buyer and seller. But I believe these hidden aspects of transactions are more common than most appraisers realize and are a source for funky values that don't seem to make sense.
I've sold houses on contract to buyers who I was willing to take a risk on by giving them favorable payment terms, but at much higher sales prices than market value. That's another quirk in how something like this can work with the negative adjustment being well in excess of the concession amount. I used to sell properties to my long term tenants with financing terms that gave them a payment that was just slightly higher than their existing rental payment, yet with a sales price in excess of market value. All they cared about was that their monthly payment was mostly the same. I got the higher sales price in exchange for taking a risk by doing the seller financing. Worked out well for everyone involved and made for some really bad comparables
