To get the best viewing experience from a large screen between 60"-69", you really need to be watching from a good distance away - generally the recommendation would be from 3 metres away from the screen - although, it's all down to personal preference at the end of the day.
There is a growing number of models now being produced in this range, but compared with smaller sizes, your options of finding a second hand 60"-69" TV for sale, are likely to be a little more limited.
The search will definitely be worth the effort, however, because what you can expect to discover is not only a super-sized screen, but models that are bursting with technology and features.
Most Used 60"-69" TVs for sale will be 4k Ultra HD, Freeview and Smart will be present as standard and you'll see a better range of curved technology within this size bracket than in many of the smaller sizes.
The very best 'extras' that particular manufacturers add to their premium models will be seen: Android TV, Playstation Now, soundbar stands, etc. Therefore, you'll be getting much more for your money than simply a very large screen.