Oh, I get the situation. (We are nearing the end of an overhaul of a country home with "delayed maintenance" ourselves.)
Just the same, if there is potential, there is value, and not just to one buyer. So making a heap of money wouldn't be a piece of cake if the price was fair.
True, you have to get there before the realtor gets a whiff of it. And that's not difficult when the property is a hundred, or a thousand, miles away from the heirs, and they have no imagination, or they're busy.
I have a relative who is constantly getting calls from realtors asking him if he'd like to sell his second home, minutes from Manhattan. If it was Grandpa's house, last sold for $1500 in 1947, and located in Middle O'Nowhere, PA, realtors would not call.
Also, a realtor isn't putting a lot of energy into selling Grandpa's house. It's run down. It could be listed over a year. Taxes racking up. Notices from code enforcement. Fines. Meanwhile the realtor is off chasing the big commission.
There's potential in most houses. Most people don't see it. They do see cash on the barrelhead.