I have seldom regretted the items that I purchased,
but often
regretted those that I did not!
I've heard that said about other collectables too, normally in the form
'You never regret the <foo> you buy, only the <foo> you don't'
(where
<foo> is computers, cameras, clocks, stamps, etc as appropriate).
In general, I've found it to be true, at least provided the money spent
on the items is not otherwise required for essentials like food, shelter,
electricity, etc...
-tony