My realtor called a roofing company and got an estimate on the cost of repairing the trouble with the roof. The seller's agent agreed to place that amount +15% in an escrow account at the title company, to pay the roofers. It came out of his commission. Apparently, he couldn't reach the sellers to yell at them, and I stated categorically "If this isn't resolved today I am not buying this house ever."
Rather than lose the sale, he ate the cost.
So, I bought it.
Those of you who are happy about this may feel free to congratulate me now. Those of you who think I have made a huge mistake may feel free to keep those thoughts to themselves. >:) It's over now.