if you can get credit for the job from the seller, do it. if you can't, here's what you should do: 1. get a quote from some well know contractors to whom you will work with for the job after closing for the jobs (estimate the cost by a 3rd party); 2. write an addendum asking the seller to pay the bill via your escrow company after closing(get agreement with both parties); 3. request your escrow to withhold the payment from seller's proceed ( request escrow to withhold the payment for the job).