Buying Zeppelins C13, C14 & C15

(OK, below I should have said early 1980s instead of 1970s.  My worsening memory is showing again...)

The supply of those Zeppelins is more than the demand of those who can afford it. If you want to "invest" in stamps, there are better choices.

That being said, if you were to "invest" in C13-C15, consider only XF MNH or better with no faults; or for used, XF on complete clean cover with good cancels/markings or historical significance. Anything less than that, you have nearly no chance of beating a 10-12% standard rate of return, plus you will need to factor in buying/selling commission (can easily total 25%-35% for decent auction house) -- in other words, anything less than that, you would be better off investing in something else.

Keep in mind that full MNH panes and large lots of MNH of well-centered multiples/singles still get sold/traded among dealers. Just check the stamp selling sites and you will see plenty of Zeps of all grades/conditions available.  That's a sure sign that supply far exceeds payable demand.

If you want to do long-term investing in stamps, I would suggest you only consider stamps that pop up in auctions at most 1-2 times a year.  Those are stamps that consistently increase in value, will often beat the estimate (surprise, if you look at results from most major auction houses, most hammer prices do not beat the pre-auction estimate!), and will get multiple bidders.  An extreme example is the 1c Magenta -- looks like a faded piece of junk, and yet see how much the value increases each time it gets put up for sale!

The price of Zeppelins has never come close to returning to its peak value in the 1970s.  If you bought Zeppelins in the 1930s and sold today, you would have beaten the standard rate of return on investment.  If you bought Zeppelins in the 1970s, you would have suffered a significant loss.  If you buy today, I find it hard to expect beating the standard ROR without going to the highest quality/demand Zep stamp/cover.

Here is an older, but still useful article:  Stamp investment can be successful, but comes with risk.

Just my opinion.  Others may have a different valid take on this.

Everything posted has been spot on.

I own a nice set of MNH certified graded XF-Superb, and I could Maybe,maybe get what I paid for it several years ago.

I'm posting, because I've never understood prices for Zeps. I own quite a few stamps that are far more rare than a Zep, but don't command nearly the same price

$2,600 sounded rather high to me, so I checked the 2013 Scott Catalogue values for C13-C15:

$1,900 for set, mint-never-hinged
$1,155 for set, mint-hinged
$1,140 for set, used

All values in USD. Just FYI