SELLER CONCESSIONS:
This is the topic that has many in the lending business very confused. Why? because some appraisers adjust for this on the sales grid while others do not. The truth is, if a concession is given by the seller in the form of cash, it must be adjusted out dollar for dollar. 

FAQ:
Q) Why must seller concessions be adjusted? it seems typical in the market, everyone is doing it.
A) The purpose of adjusting comparable sales for concessions is to provide an indication of value of the subject property based on the definition of value. Even though the sales concession might be “typical” of the market and paid by the seller in virtually all transactions, the sale price is impacted by the concession. 
Q) How is a sales price impacted by seller concessions? Builders seem to give cash concessions all the time on new construction homes.
A) It is important to remember that cash concessions given to a buyer is usually to help the buyer afford the closing cost of buying a home.
further, cash concessions impact the sales prices as follows. Example: if an agreed sale price is $100,000 and the seller is giving $10,000 in closing help the sale price if typically affected by at least $10,000. But not just for the buyer, it also affects everyone in the transaction. Here's why,
Lets say on the above mentioned sale, the sellers closing cost are 5% of the sales price, and the seller is paying 5% to the agent in commission. Ok,
so with a sale price of $100,000 minus 5% commission -($5,000) and minus 5% closing cost -($5,000) and then minus $10,000 seller concessions to the buyer, the net proceeds to the seller is $80,000. Ok, same example only this time the buyer says instead of giving concessions of $10,000, lets just lower the price by that amount to $90,000. Seller will typical agree every time, and here's why. Now we have a sales price of $90,000, minus the same 5% closing cost -($4500) and minus the same 5% commission to the agent is -($4500), Net proceeds to the seller is now $81,000. So the seller makes an extra $1,000 on the sale of his/her life's investment, both the seller and the buyers are paying less in taxes, closing cost etc. and the buyer is not financing an extra $10,000 for the next 30 years. I mentioned how this affects every one in the transaction, Yes, the lender is assured that the home is not over inflated and that the buyer can most like afford the home they are buying, The agents, well sadly they make a little less in commission. But at the end of the day, the appraiser has done his/her job, protected the buyer, lender and the market place.