Mark - great question - I'm sure we all have a lot of these.
For me, I am primarily VERY glad I took a grand tour of Scotland and Ireland in 1987, and played so many great courses then, with the guest prices being 1/10 of what they are now in some places, 1/4 at all - not to mention the crowds being about the same proportion.
Here are a few others: I am very glad I played Spanish Bay back when it first opened, and when it was fescue. I'm glad I played MPCC-Dunes before the renovation, just so I could see what an improvement was done there. I'm glad I played MPCC-Shore before it was re-done, just because it was such a damn fine course with such great greens, that I appreciate the memory, even if today's course is overall likely an improvement. I'm glad I played several others in NorCal and SoCal before they were developed out of existence...
TH
ps - and I too am very glad I played Bandon and Pacific back when Pacific first opened, when prices were more reasonable. Good call MDugger.