Generally it is better for the buyer to make repairs. The reason is, the seller will usually make a simpler and cheaper repairs because they are going to be leaving the home. A buyer will choose the right repair for their future home. One of the worst cases of a seller's repair we have seen was when we found the roof to be past it's lifespan. The seller quickly put on a new roof for the buyers which was the poorest roof installation we had seen to date.