What Has Turned Out To Be Your Best Collectible Investment? You're Worst?

My best stamp investment was a used U.S. Scott #70. I think I paid maybe $60 for it. There was something about the listing that made me think it was too good to be true, so I sent to the Philatelic Foundation for expertization. It came back graded VF-80, no flaws, and correctly identified as a #70c, which catalogs around $1,800.

Best? Surprisingly enough, playing cards. 7-11 produced a special deck with their logo on it and had it printed with USPCC, the producers of "Bicycle" playing cards and arguably the greatest playing card producer ever. They were in very select stores only in the U.S. I virtually bought out the closest store that had them, and sold them to a playing card collector overseas for just about triple what I spent.

Worst? There's unfortunately a few. Most memorable would be when I bought a lot of postcards that had very common but old U.S. stamps on 'em. This was back when I fell victim to the "if it's old it HAS to be at least a little valuable" mentality. Thankfully it's a lesson I learned from. To be fair, some of the best life lessons are the ones that sting the most. In a way, I'm glad it happened- if only for the educational aspect.

Mint postage has turned out to be both my best and worst investment.
Worst was the stuff I bought myself as a kid in the 1970s, best was all the stuff I have since picked up on ebay at a fraction of face and then used to send parcels.

Best stamp investment------Many big junk lots at various stamp auctions . Many being huge bulk lots ,I had 3 or 4 tons of boxes all piled high to be worked on in the 1980's and 1990's the auction firms were all happy I was taking the stuff ,they even threw in more bulk stuff because nobody wanted it . THEN ebay STARTED ,and then the world changed.

Best stamp investment: All of them, at least in recent years. I get enjoyment out of collecting, mounting and admiring them which is something that has no price tag. I sold my childhood album for about $60 as a teen in probably 1990, which was a fair price for the book at the time. (Nothing of real serious monetary value there.) Since then, have never sold or tried to sell a stamp. Thankfully am in the postition that I don't have to consider haing to sell stamps; but yearn for the old days of stamp clubs when you could actually trade.

If I could find a kid or family who would genuinely appreciate some of my duplicates and give them away to someone who really would cherish them as a true collector, that would probably be the biggest investment/gain.

What do You think,is the long term (20+ years before sale) investing in stamps a good idea?
And I dont think about 1000 USD+ cat value stamps,but about some middle class. For example british commonwealth 100-200 USD catalogue value series.