There are a few good old boats around,but it is difficult to know which is good and which is bad.A survey definately helps to say which is which, but for various reasons can't be taken as gospel.Best to buy the youngest boat in your budget and commission your own survey.There are many parts of a boat that are hidden or inaccesible without removing trim or flooring and any horrors may come to light some time after you have bought the boat.
It's a bit like taking up with a new woman, in that you don't know what you've really got untill you live with her for a year.
I am giving a rather pessimistic view, but I have been 'done' a couple of times. (Both boats and women) 😢