I spent the whole of a summer holiday working to pay £25 for a second hand red label Yamaha FG140 way back in 1971. I have had many offers for it but won't part with it. It still sounds as sweet as a nut. When amplified it sounds bloody great!
I've tried Taks, Martins, Gibsons and hand built jobs but I still prefer my old beauty. The sound suits me and that's all that matters.
The original Martin copies (mine is one of them) were made from well seasoned wood and should last virtually forever unlike more modern guitars.