The rule of thumb I learned a long time ago is that a person should spend the same amount of money on glass as they did the rifle. Some people believe you should spend double the amount on glass that you do the rifle. That one is fairly new to me and I think it may be a bit extreme. But scopes are generally forever while rifles can come and go. If you buy a really good scope you will never have a good reason to get rid of it unless it breaks and that doesn't happen that often with a really good scope.
My stainless 60 has a Nikon ProStaff on it. It's a 3-9X40. Yeah I know that's a lot less than a 60SS costs but it is about the same as a standard 60 costs. So I always figured it was a good match for the Marlin. I do wish it had AO but it hasn't been much of a problem really. Supposedly a 9X scope won't have a big parallax problem depending on where the scope is designed to be parallax free. For most scopes that's 100 yards. For many rimfire scopes it's 50 yards. But for the Nikon I mentioned it's 100 yards. So in reality the ONLY distance there will be zero need for AO adjustment is 100 yards exactly.
The thing is there isn't a lot of variation on a scope without AO at distances up to 100 yards. But the real skinny on this issue is that most AO issues on rimfire rifles can be dealt with by consistent eye placement and alignment with the scope. It's a lot tougher than it sounds. But unless you can do that and really even if you can do it you will never be as good of a shooter as your rifle unless you master parallax in some way. The way I do it by good old fashioned Kentucky windage. Or I use AO and I practice with it until I can make it work exactly right. That is certainly the best option but I've been able to make scopes work without it probably because I grew up without AO and if you wanted to shoot well you learned to deal with the problems with experience and KY windage. That's the one thing that can make you a decent shooter no matter what but you can be a better shooter with AO.
So the rub is that you really need AO even on rimfire rifles shooting under 100 yards and with a scope that is 9X or less. It will make you better but it's still possible to shoot fairly well without it. Just don't expect to shoot .1" groups at 100 yards or anything.
Again I've done OK with my Nikon scope. You may want a scope with AO though. But glass quality does matter. Light gathering does matter. You pays your money and you lives with your choice basically. There are good choices with and without AO. You generally get better glass for your money without AO. If you have to pay for AO you have to lose something else somewhere. That's the long and short of it but it's not set in stone or anything. Good compromises do exist.
The bottom line. Listen to the reviews, sift through the hype, look through scopes when you can and find out how bad AO is with them. You'll need to learn how. Basically it's a matter of moving your head and checking to see if the crosshair moves.
Because this issue is about as clear as mud there is no really good answer to your question. There are only suggestions and reports. Science doesn't do this justice unless you have a PhD in light physics. You pays your money and you takes your chances friend. Good luck. Again I've done well with my Nikon or at least I think so. But what do I know?
