It's all about how much you like the amp and how much $$$. If you like it and they sell like used price, nothing wrong buying it. You just do the recap.
Hell, I'd just turn it on and see what happen......better yet, tell the seller you want to listen before you buy, if it smoke, it's not your problem. Hell my Acurus is 20 years old and I have no plan to recap it. I compared the sound with my total restored Stasis amp that is double the price, barely hear any difference.
I don't do service, so I don't have a lot of experience on maintenance. But I just feel recap is not particularly that important. When I first bought my Nakamichi Stasis amp, I knew the caps were old, I looked on the scope and it shows the spike is too high on two of the caps already. I did recapped, I could not hear a dent of a difference. I know people disagree with this, but this is how I roll. It it does not smoke, it's all good. You fix it when you need to.