SELL THAT HOUSE: APPEARANCE IS EVERYTHING
Salability is directly related to appearance.
If you want to buy a car, but it has a dented door, then you will probably pass on the car rather than pay $2000 for a new door, even if the seller discounts the price by $2,000. So a car that would be worth $20,000 suddenly becomes worth nothing if it has a defect.
Likewise with a house, if it were worth $300,000 in good condition, it may suddenly be worth nothing if it needed carpet and paint that may only cost $10,000.
Allowance is Not Enough
You could suggest an allowance, but typically that is not enough. The Buyers decision has already been "emotionally" made.
On the surface, this makes no sense, but in practice, believe me, this is what happens. A home that only needs carpet and paint, and hence shows poorly, will sit on the market for days, but with a few thousand invested in paint and carpet to spiff it up, it sells in a week.
Discount Must be More Than Cost of Repair
Further discounting the price may be an alternative; however the discount would generally need to include the cost of the fix-up plus another 30%. Why should the Buyer deal with your problem, if they are going to get nothing out of it?
Many sellers ask how much more they will get if they do any particular improvement to a house. This is the wrong question when it comes to things like paint and carpet. More appropriately, they should be asking what they need to do simply to sell the house at all.