Had one, like that, I sold for $400, that its only problem that was worrying me, was the Hydro was a bit worn on it. I was able to replace the trans oil with some Synthetic gear lube, that had the viscosity of motor oil. But it was worked hard. Haven't heard anything from the buyer since he bought it....so I guess it is holding up.
That one in the ad from Racine, seems to be just some normal usage. It ought to be alright if the engine is good.