To my way of thinking the older Guild guitar of any string number is the best value for a quality guitar around. Even the new off shore Guilds, GADs, are superior instruments, dollar for dollar.
My 63 F-30 is still a fine sounding guitar. My Martin's are nice but they aren't the Guild F 30. I was given a 64 Martin D 12-20 that is a tinny box compared to any Guild 12 I have played from a similar age.