I did it - but not in Ireland unfortunately.
We managed to find a motivated buyer who wanted to move in next to her friend next door. In fact the neighbour found her, not us. We got market value in a stagnant 1990s US market, we were happy enough. We saved the standard US commission, whatever it was, honestly can't remember, but in the kind of slow market at the time it was a significant saving and allowed us to break even on the house (after about 3 years of owning).
There were a lot of time wasters though - that was the depressing part, having to vet potential buyers ourselves. And several people didn't show up having made appointments. You'd worry about some of the psychos out there too! At least the slow market meant there weren't that many people to not show up in the first place...
I think auctioneer commissions are pretty negotiable. Don't know though, have never sold here.