Might be someone will pay that price for a single board, up here that price would be laughed at, not because it was funny either. I've seen a lot of tree damage, plenty of dead trees, but if a tree up here did get processed I've not seen where they kept the kill area on the wood. Generally if a single larva went in, and caused a trees death they would just cut it off, and burn it, then use the rest of the Ash. They don't tend to move inside the tree more than 2' of height most of the time, but they do ramble about inside.
At Frank Miller where I buy a lot of hardwoods, they heat their kilns with all the sawdust, and really unusable offcuts that they can't sell. Everything except kill from Emerald ash borer. Not sure if they think they will cause issue, but they do burn it, but it's far away from any of their other stock. I don't know if that is driven by law, or just a thing, but I don't know any lumber milling operations where they display that. I know at the start there were a lot of laws put in place, mostly state laws that controlled interstate movement, and such. I really don't know if they are still being followed? But the burning may be addressed there.
At our old place we had planted a lot of Ash, good sturdy trees, multiple varieties. While we were still there the EAB had started it's move into Northern Ohio. We used a systemic each Spring, and this kept our Ash safe. When we sold, we told the buyers this, and I know he was doing it, because he wanted to know specific product we used. He got sick though, and they ended up selling. Not so sure she passed it along? Anyhow all the Ash are deader than dead can be now. Unless someone pointed out, this is an ASH, protect it by... Probably most peeps just saw a tree. Some scattered ash in the woods around us down here when we first moved in, all dead now. I imagine any yard trees that are Ash, and still alive, are being treated each year with a systemic. Pretty easy, just spray Dinotefuran up the tree about 5 to 6' on the bark, done. It is said to be 100% until the trees get 50" around, then ~~~~~ kinda works. Best in the Spring, and I would do it when rain wasn't in the forecast for a few days.