Congrats with the completion of your collection!
I remember the days I spent countless hours watching the Airfix and Tamiya modelkits in toyshops.
And not being able to decide which one to buy for my birthday. Shall I take the Flakpanzer 4 Wirbelwind + a box with some infantry or just the more expensive Stuka with that snake painted on the fuselage?
Those where the problems of a young kid.
The good thing nowadays with trying to get your collection completed is the internet. No need to enter each and every toyshop in every place you visit or going to second hand fairs hoping to find what you are looking for. And knowing it is not going to happen.
Everything I've been searching for for a long time - like certain comic books and its original drawings- I managed to find on sites like Ebay, Amazon and so on.
The flipside though is that so many other interesting stuff is just one mouse click away. That way I've spent (not wasted) already a considerable amount of money.