All very well to daydream but there are some very significant practicalities to consider about a scope this size. GlenD already mentioned the storage and resale problems. A scope this size is also a monster just to move from storage to use. Then there are limitations on the lowest practical magnification. For a 65" f3.5, the limit is about 250X -300X with a widest full aperture field of view of about 15 minutes of arc. As you go to wider and lower powers, you'll progressively lose more and more light. In fact if you jump up to something like an LE50, then you'll have a magnification of 115X, a 27 minute field of view but exit pupil limitations will restrict your eye to only receiving 17% of the light coming from the main mirror similar to a 28" mirror.
There will be very few nights where seeing conditions allow you to use even the lowest 250X magnification.
Might be a good scope for chest beating at star parties but very limited in use. Depending upon your budget and the condition of your back, 16-30 inch scopes around f3.5-f5 are probably the sweet spot for those chasing large amateur apertures.
