How much is to much?

The year was 2006 and John a collector of Morgan Dollars purchased a professionally graded 18xx-S MS63 for $50.00. John was happy with his purchase but wished he could afford a higher grade. Ken a friend of John's also was a Morgan collector. Ken decided he wanted the best so searched for a found the same year - a 18xx-S in MS67. Ken paid $4800 for his superb high quality coin of which only 9 existed at MS67. Ken was also extremely pleased and proud of his acquisition. Two years passed and the year 2008 arrived and in the preceding 24 months an additional 200 188xx-S MS63's were certified by the graders. John's coin was still worth about $50-$55. An additional (6) MS67's 18xx-S were also found and graded. Now there were 15 of these nice MS67 beauties but due to the increase in supply one could be had for about $3800. If Ken was not concerned about values then his purchase was sound as ownership was his reward. Each of us must ask, as in this case $1000 worth the pride of ownership.

It should be pointed out that John took very little risk while Ken assumed a much greater risk and had no additional MS67's been found Ken's coin may have been valued a say $6000.

This fictional short short story begs the question: Is this a good place to take such finanical risks?